Document Contents

This preliminary prospectus supplement relates to an effective registration statement under the Securities Act of 1933, as amended, but the information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

The notes will bear interest at a rate of % per year. Interest on the notes is payable semi-annually in arrears on and of each year, beginning on , 2019. The notes will mature on , .

We may redeem some or all of the notes at any time and from time to time prior to maturity at the applicable redemption price discussed in this prospectus supplement under the heading "Description of the Notes and the Guarantee—Optional Redemption."

The notes will be unsecured and will rank equally in right of payment with all of the other unsecured, unsubordinated indebtedness of CubeSmart, L.P. from time to time outstanding. CubeSmart, the sole general partner of CubeSmart, L.P., will guarantee payment of the principal and interest on the notes. The guarantee of the notes will be an unsecured and unsubordinated obligation of CubeSmart. CubeSmart has no material assets other than its investment in CubeSmart, L.P.

Investing in the notes involves risks. See "Forward-Looking Statements" in this prospectus supplement, "Risk Factors" beginning on page S-8 of this prospectus supplement and "Risk Factors" set forth in our Annual Report on Form 10-K for the year ended December 31, 2017 and other filings with the Securities and Exchange Commission incorporated by reference in this prospectus supplement and in the accompanying prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

We expect that delivery of the notes will be made to investors through the book-entry delivery system of The Depository Trust Company for the accounts of its participants, including Clearstream Banking S.A. and Euroclear Bank, SA/NV, as operator for the Euroclear System, against payment in New York, New York on or about , 2019.

You should rely only on the information contained or incorporated by reference in this prospectus supplement, the accompanying prospectus or any applicable free writing prospectus filed with the Securities and Exchange Commission, or SEC, in connection with this offering. We have not, and the underwriters have not, authorized anyone to provide you with additional or different information. If any person provides you with additional or different information, you should not rely on it. Neither we nor the underwriters are making an offer to sell or soliciting an offer to buy securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus, any such free writing prospectus and the documents incorporated by reference herein and therein is accurate only as of their respective dates or on the date or dates which are specified in these documents. Our business, financial condition, results of operations and prospects may have changed since those dates.

This document consists of two parts. The first part is this prospectus supplement, which describes the specific terms of this offering and also adds to, or updates, information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part, the accompanying prospectus, dated March 17, 2017, gives more general information about our notes and other securities we may offer from time to time, some of which may not apply to this offering.

You should carefully read this prospectus supplement, the accompanying prospectus and the additional information incorporated by reference herein and therein before investing in the notes offered hereby. See "Incorporation of Certain Information By Reference" and "Where You Can Find More Information" in this prospectus supplement and the accompanying prospectus. These documents contain important information that you should consider before making your investment decision. This prospectus supplement and the accompanying prospectus contain the terms of this offering of notes. This prospectus supplement may add to, update or change the information contained in the accompanying prospectus and the information incorporated by reference herein and therein. To the extent that there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or any document incorporated by reference that we file with the SEC under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), prior to the date hereof, on the other hand, the information in this prospectus supplement shall control. In addition, any statement in a filing we make with the SEC after the date of this prospectus supplement that adds to, updates or changes information contained in this prospectus supplement, the accompanying prospectus or an earlier filing we made with the SEC shall be deemed to modify and supersede such information in this prospectus supplement, the accompanying prospectus or the earlier filing.

As used in this prospectus supplement, unless the context otherwise requires, references to "CubeSmart" refer to CubeSmart, a Maryland real estate investment trust; references to the "Operating Partnership" refer to CubeSmart, L.P., a Delaware limited partnership; and references to "we," "us," "our" or similar expressions refer collectively to CubeSmart and its consolidated subsidiaries (including the Operating Partnership).

This prospectus supplement, the accompanying prospectus and the documents and information incorporated by reference into this prospectus supplement and the accompanying prospectus contain certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the "Securities Act"), and Section 21E of the Exchange Act. Forward-looking statements include statements concerning our plans, objectives, goals, strategies, future events, future revenues or performance, capital expenditures, financing needs, plans or intentions relating to acquisitions and other information that is not historical information. In some cases, forward-looking statements can be identified by terminology such as "believes," "expects," "estimates," "may," "will," "should," "anticipates," or "intends" or the negative of such terms or other comparable terminology, or by discussions of strategy. Such statements are based on assumptions and expectations that may not be realized and are inherently subject to risks, uncertainties and other factors, many of which cannot be predicted with accuracy and some of which might not even be anticipated. Although we believe the expectations reflected in these forward-looking statements are based on reasonable assumptions, future events and actual results, performance, transactions or achievements, financial and otherwise, may differ materially from the results, performance, transactions or achievements expressed or implied by the forward-looking statements. As a result, you should not rely on or construe any forward-looking statements in this prospectus supplement, the accompanying prospectus or the documents and information incorporated by reference into this prospectus supplement or the accompanying prospectus,

or which management or persons acting on their behalf may make orally or in writing from time to time, as predictions of future events or as guarantees of future performance. We caution you not to place undue reliance on forward-looking statements, which speak only as of the date of this prospectus supplement, the dates of the documents incorporated by reference herein or as of the dates otherwise indicated in such forward-looking statements, as applicable. All of our forward-looking statements, including those contained or incorporated by reference in this prospectus supplement or the accompanying prospectus are qualified in their entirety by this statement.

There are a number of risks and uncertainties that could cause our actual results to differ materially from the forward-looking statements contained in, contemplated by or incorporated by reference in this prospectus supplement or the accompanying prospectus. Any forward-looking statements should be considered in light of the risks and uncertainties referred to in this prospectus supplement and the accompanying prospectus and our Annual Report on Form 10-K for the year ended December 31, 2017 and subsequent filings with the SEC that are incorporated by reference in this prospectus supplement and in the accompanying prospectus. These risks include, but are not limited to, the following:

Given these uncertainties and risks, prospective investors are cautioned not to place undue reliance on forward-looking statements. Except with respect to such material changes to our risk factors as may be reflected from time to time in our quarterly filings or as otherwise required by law, we are under no obligation to, and expressly disclaim any obligation to, update or revise any forward-looking statements included or incorporated by reference in this prospectus supplement or the accompanying prospectus, whether as a result of new information, future events or otherwise. Because of the factors referred to above, the future events discussed in or incorporated by reference in this prospectus supplement or the accompanying prospectus may not occur and actual results, performance or achievement could differ materially from those anticipated or implied in the forward-looking statements.

SUMMARY

The information below is only a summary of more detailed information included elsewhere or incorporated by reference into this prospectus supplement and the accompanying prospectus. This summary does not contain all the information that is important to you or that you should consider before you invest in the notes. The other information is important, so please carefully read this prospectus supplement and the accompanying prospectus, as well as the information incorporated by reference herein and therein before you invest in the notes.

Overview

CubeSmart is a self-administered and self-managed REIT focused, through the Operating Partnership, primarily on the ownership, management, operation, acquisition and development of self-storage properties in the United States.

Stores

As of September 30, 2018, we owned 490 self-storage properties located in 23 states and in the District of Columbia containing an aggregate of approximately 34.5 million rentable square feet. In addition, as of September 30, 2018, we managed 582 stores for third parties (including 149 stores containing an aggregate of approximately 8.9 million rentable square feet as part of five separate unconsolidated real estate ventures) bringing the total number of stores which we owned and/or managed to 1,072.

As of September 30, 2018, we owned stores in the District of Columbia and the following 23 states: Arizona, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Maryland, Massachusetts, Minnesota, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Tennessee, Texas, Utah and Virginia. In addition, as of September 30, 2018, we managed stores for third parties in the District of Columbia and the following 35 states: Alabama, Arizona, California, Colorado, Connecticut, Florida, Georgia, Illinois, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Mississippi, Missouri, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, and Wisconsin.

Our self-storage properties are located in major metropolitan areas as well as suburban areas and have numerous customers per store. No single customer represented a significant concentration of our 2017 revenues.

Corporate

CubeSmart was formed in July 2004 as a Maryland REIT. CubeSmart owns its assets and conducts its business through the Operating Partnership and its subsidiaries. CubeSmart controls the Operating Partnership as its sole general partner and, as of September 30, 2018, CubeSmart owned an approximately 98.9% interest in the Operating Partnership. The Operating Partnership has been engaged in virtually all aspects of the self-storage business, including the development, acquisition, management, ownership and operation of self-storage properties.

Our executive offices are located at 5 Old Lancaster Road, Malvern, Pennsylvania 19355 and our telephone number is (610) 535-5000.

We maintain a website at www.cubesmart.com. We have not incorporated by reference into this prospectus supplement or the accompanying prospectus the information in, or that can be accessed through, our website, and you should not consider it to be a part of this prospectus supplement or the accompanying prospectus.

THE OFFERING

The summary below describes the principal terms of the notes. Certain of the terms and conditions described below are subject to important limitations and exceptions. The sections entitled "Description of the Notes and the Guarantee" in this prospectus supplement and "Description of the Debt Securities" in the accompanying prospectus contain a more detailed description of the terms and conditions of the notes and the indenture governing the notes.


Issuer		CubeSmart, L.P.
Guarantor		CubeSmart.
Securities Offered		$ principal amount of % Senior Notes due .
Maturity Date		The notes will mature on , .
Interest		The notes will bear interest at a rate of % per annum. Interest will be payable semi-annually in arrears on and of each year, beginning on , 2019. Interest will accrue from, and including, , 2019.
Optional Redemption		We may redeem the notes, in whole or in part, at any time prior to maturity. If the notes are redeemed before , (the "Par Call Date"), the redemption price will equal the greater of: (i) 100% of the principal amount of the notes then outstanding to be redeemed; and (ii) the sum of the present values of the remaining scheduled payments of principal of, and interest on, the notes to be redeemed (not including any accrued and unpaid interest), assuming that such notes matured on the Par Call Date, discounted to the redemption date on a semi-annual basis at the applicable Treasury Rate (defined below) plus basis points (the "Make-Whole Premium"); plus accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, the redemption date. If the notes are redeemed on or after the Par Call Date, the redemption price will equal 100% of the principal amount of the notes then outstanding to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date.
		See "Description of the Notes and the Guarantee—Optional Redemption" in this prospectus supplement.
Ranking		The notes will be unsecured obligations of the Operating Partnership and will rank equally in right of payment with each other and with all of the Operating Partnership's other unsecured, unsubordinated indebtedness. The notes will be effectively subordinated to the Operating Partnership's secured indebtedness and the indebtedness and other liabilities of the consolidated subsidiaries of the Operating Partnership. See "Risk Factors—The effective subordination of the notes and the guarantee may reduce amounts available for payment of the notes, the Make-Whole Premium, and the guarantee" in this prospectus supplement.


Guarantee		CubeSmart will fully and unconditionally guarantee the Operating Partnership's payment obligations on the notes. The guarantee will be an unsecured and unsubordinated obligation of CubeSmart. CubeSmart, however, has no material assets other than its investment in the Operating Partnership.
Certain Covenants		Under the indenture, we have agreed to certain restrictions on our ability to incur debt and to enter into certain transactions. See "Description of the Notes and the Guarantee—Covenants" in this prospectus supplement and "Description of the Debt Securities" in the accompanying prospectus.
Form and Denominations		We will issue the notes in fully registered form in denominations of $2,000 and integral multiples of $1,000 in excess thereof. The notes will be represented by one or more global securities registered in the name of a nominee of The Depository Trust Company, or DTC. You will hold beneficial interests in the notes through DTC, and DTC and its direct and indirect participants will record your beneficial interest on their books. Except under limited circumstances, we will not issue certificated notes.
Use of Proceeds		We estimate that the net proceeds from the sale of the notes in this offering will be approximately $ million after deducting the underwriting discount and our estimated transaction expenses relating to this offering and payable by us. We intend to use the net proceeds from this offering of notes to repay $200.0 million of outstanding indebtedness incurred under the unsecured term loan portion of our credit facility maturing in January 2019 and for working capital and other general corporate purposes, which may include repayment or repurchase of other indebtedness. See "Use of Proceeds" in this prospectus supplement.
Market for Notes		The notes are a new issue of securities with no established trading market. An active or liquid market may not develop for the notes or, if developed, may not be maintained.
No Listing		We have not applied, and do not intend to apply, for the listing of the notes on any securities exchange or for quotation on any automated quotation system.
Risk Factors		See "Risk Factors" beginning on page S-8 of this prospectus supplement and beginning on page 12 of our Annual Report on Form 10-K for the year ended December 31, 2017 as well as other information included or incorporated by reference in this prospectus supplement or accompanying prospectus, to read about certain risks you should consider before making an investment in the notes.


Tax Consequences		Certain federal income tax considerations of purchasing, owning and disposing of the notes are summarized in "Material United States Federal Income Tax Considerations" on page S-23 of this prospectus supplement, which supplements the discussion under the heading "Material United States Federal Income Tax Considerations" in Exhibit 99.1 to our Annual Report on Form 10-K for the year ended December 31, 2017, which discussion is incorporated by reference into this prospectus supplement and supersedes the discussion under "Material Federal Income Tax Considerations" in the accompanying prospectus. In addition, please refer to the discussion of material United States federal income tax considerations relating to the purchase, ownership and disposition of common shares and preferred shares of CubeSmart and other debt securities of the Operating Partnership, and the qualification and taxation of CubeSmart as a REIT also in Exhibit 99.1 to our Annual Report on Form 10-K for the year ended December 31, 2017.

An investment in the notes involves a high degree of risk. In consultation with your own financial and legal advisers, you should consider carefully, among other matters, the factors set forth below as well as the risk factors beginning on page 12 of our Annual Report on Form 10-K for the year ended December 31, 2017 and in any subsequent filings that are incorporated by reference in this prospectus supplement or the accompanying prospectus before deciding whether an investment in the notes is suitable for you. Additional risks not presently known to us or that we currently deem immaterial may also adversely affect our business operations. These risks could materially adversely affect, among other things, our business, financial condition or results of operations.

CubeSmart has no material assets other than its investment in the Operating Partnership.

CubeSmart will fully and unconditionally guarantee the Operating Partnership's payment obligations with respect to the notes. The guarantee will be an unsecured and unsubordinated obligation of CubeSmart and will rank equally with CubeSmart's other unsecured and unsubordinated obligations. As of September 30, 2018, CubeSmart and its consolidated subsidiaries had unsecured and unsubordinated obligations of approximately $1,544.3 million. In addition, as of September 30, 2018, CubeSmart and its consolidated subsidiaries had secured indebtedness obligations aggregating approximately $106.8 million consisting of mortgage notes payable. Holders of the notes will be relying solely upon the Operating Partnership, as issuer, and CubeSmart, as guarantor, to make payments in respect of the notes. CubeSmart has no material assets other than its investment in the Operating Partnership.

The effective subordination of the notes and the guarantee may reduce amounts available for payment of the notes and the guarantee.

Both the notes and the guarantee will be unsecured and therefore will be effectively subordinated to our secured indebtedness to the extent of the value of the assets securing such indebtedness. The holders of our secured debt may foreclose on the assets securing such debt, reducing the cash flow from the foreclosed property available for payment of unsecured debt, including the notes and the guarantee. The holders of our secured debt also would have priority over unsecured creditors in the event of our bankruptcy, liquidation or similar proceeding. The notes effectively will also be subordinated to the indebtedness and other liabilities of the consolidated subsidiaries of the Operating Partnership because creditors of any of our subsidiaries will generally be entitled to payment of their claims from the assets of the subsidiaries before any of these assets are made available to us. As of September 30, 2018, the Operating Partnership and its consolidated subsidiaries had secured indebtedness of approximately $106.8 million. The indenture governing the notes will permit us and our subsidiaries to incur additional secured and unsecured indebtedness if the conditions specified in the indenture are met. See "Description of the Notes and the Guarantee—Covenants" in this prospectus supplement and "Description of the Debt Securities" in the accompanying prospectus.

The notes will restrict, but will not eliminate, our ability to incur additional debt or prohibit us from taking other actions that could negatively impact holders of the notes.

We will be restricted from incurring additional indebtedness under the terms of the notes and the indenture governing the notes. However, these limitations are subject to significant exceptions. See "Description of the Notes and the Guarantee—Covenants—Limitations on Incurrence of Indebtedness" in this prospectus supplement. Our ability to recapitalize our debt and capital structure, incur additional debt, secure existing or future debt or take other actions not limited by the terms of the indenture and the notes, including repurchasing indebtedness or common or preferred shares or paying dividends, could negatively affect our ability to make payments in respect of the notes when due.

The market price of the notes will depend on many factors that may vary over time and some of which are beyond our control, including, among others, the following:

As a result of these factors, you may be able to sell your notes only at prices below those you believe to be appropriate, including prices below the price you paid for them.

An increase in interest rates could result in a decrease in the market value of the notes.

In general, as prevailing market interest rates rise, notes bearing interest at a fixed rate decline in value. Consequently, if you purchase the notes and interest rates increase, the market value of the notes may decline. We cannot predict the future level of interest rates.

CubeSmart is required to make distributions to its shareholders and therefore the Operating Partnership must make distributions to CubeSmart, which could negatively affect our ability to make payments in respect of the notes when due.

To maintain its status as a REIT for U.S. federal income tax purposes, CubeSmart must distribute to its common and preferred shareholders at least 90% of its taxable income (excluding capital gains) each year. CubeSmart depends upon distributions or other payments from the Operating Partnership to make distributions to its common and preferred shareholders. These distributions could negatively impact our ability to make payments in respect of the notes when due.

Our credit ratings may not reflect all risks of your investment in the notes.

Our credit ratings are an assessment by ratings agencies of our ability to pay our debts when due. Consequently, real or anticipated changes in our credit ratings will generally affect the market value of the notes. These credit ratings may not reflect the potential impact of risks relating to the structure or marketing of the notes. Agency ratings are not a recommendation to buy, sell or hold any security, and may be revised or withdrawn at any time by the issuing organization. Each agency's rating should be evaluated independently of any other agency's rating.

There can be no assurance that we will be able to maintain our current credit ratings. In the event that our current credit ratings are downgraded or removed, or if any ratings agency indicates that it has placed any such credit rating on a so-called "watch list" for a possible downgrade or removal or

otherwise indicates that its outlook for that rating is negative, we would most likely incur higher borrowing costs and experience greater difficulty in obtaining additional financing, which could in turn have a material adverse effect on our financial condition, results of operations, and liquidity.

We will require a significant amount of cash to service our debt. Our ability to generate cash depends on many factors beyond our control.

Our ability to make payments on and to refinance our debt, including the notes, and to fund planned capital expenditures, will depend on our ability to generate cash in the future. This is subject to general economic, financial, competitive and other factors that may be beyond our control.

Based on our current operations, we believe our cash flow from operations, available cash and available borrowings under our credit facilities will be adequate to meet our future liquidity needs for the next several years barring any unforeseen circumstances which are beyond our control. We cannot assure you, however, that our business will generate sufficient cash flow from operations or that future borrowing will be available to us under our credit facilities or otherwise in an amount sufficient to enable us to pay our debt, including the notes, or to fund our other liquidity needs. We may need to refinance all or a portion of our debt, including the notes, before maturity. We cannot assure you that we will be able to refinance any of our debt, including our term loan and credit facilities, or the notes, on commercially reasonable terms or at all.

The notes will be a new issue of securities with no established trading market. We do not intend to apply for listing of the notes on any securities exchange or for quotation on any automated quotation system. We cannot assure you that an active or liquid trading market for the notes will develop. If a trading market were to develop, the notes could trade at prices that may be higher or lower than their initial offering price and this may result in a return that is greater or less than the applicable interest rate on the notes, depending on many factors, including, among others, prevailing interest rates, our financial results, any decline in our creditworthiness and the market for similar securities.

We estimate that the net proceeds from the sale of the notes in this offering will be approximately $ million, after deducting the underwriting discount and estimated transaction expenses related to this offering and payable by us.

We intend to use the net proceeds from this offering of notes to repay $200.0 million of indebtedness incurred under the unsecured term loan portion of our credit facility maturing in January 2019 and for working capital and other general corporate purposes, which may include repayment or repurchase of other indebtedness.

As of January 23, 2019, we had $200.0 million outstanding under the unsecured term loan portion of our credit facility maturing in January 2019, which currently bears interest at the London Interbank Offered Rate (LIBOR) plus 1.30% per annum based on the credit ratings for the Operating Partnership's unsecured debt.

The underwriters in this offering and/or their affiliates act as lenders and/or agents under our credit facility and our term loan facility and, in some cases, provide mortgage loans on certain of our properties. As described above, we intend to use a portion of the net proceeds of this offering to repay all of the outstanding indebtedness under the unsecured term loan portion of our credit facility and may repay or repurchase other indebtedness, and those lenders and/or agents therefore will or may receive a portion of the net proceeds from this offering through the repayment of those borrowings. See "Underwriting (Conflicts of Interest)—Conflicts of Interest" in this prospectus supplement.

The following table sets forth the Operating Partnership's capitalization as of September 30, 2018 (1) on an actual basis and (2) as adjusted to give effect to the consummation of this offering and the use of net proceeds as described under "Use of Proceeds". This table should be read in conjunction with our consolidated financial statements and the notes thereto incorporated by reference into this prospectus supplement.

	September 30, 2018

	Actual		As Adjusted
	(in thousands) (unaudited)
Cash and Cash Equivalents	$	3,387	$

Debt:
Revolving credit facility(1)	$	94,250	$	94,250
Unsecured term loans, net		299,699		99,699
Mortgage loans and notes payable, net		109,058		109,058
4.800% senior notes due 2022, net		249,045		249,045
4.375% senior notes due 2023, net		299,178		299,178
4.000% senior notes due 2025, net		298,166		298,166
3.125% senior notes due 2026, net		296,869		296,869
% senior notes due , net

Total debt, net		1,646,265

Limited Partnership interests of third parties		58,446		58,446
Capital:
Total capital		1,702,022		1,702,022

Total Capitalization	$	3,406,733	$

The following description of the particular terms of the notes and the guarantee offered by this prospectus supplement supplements the description of the general terms and provisions of the debt securities and the guarantee set forth in the accompanying prospectus under "Description of the Debt Securities."

The notes will be issued under an indenture dated September 16, 2011, which CubeSmart and the Operating Partnership have entered into with the U.S. Bank National Association, as trustee, as amended and supplemented by a Sixth Supplemental Indenture to be dated as of the closing date of this offering (collectively, the "indenture"). The indenture is subject to and is governed by the Trust Indenture Act of 1939, as amended, or the TIA. The notes are subject to the provisions contained in the indenture and those made part of the indenture by the TIA. The notes are subject to all those terms and investors are referred to the indenture and the TIA for a statement of these terms.

The following description summarizes selected provisions of the indenture and the notes. It does not restate the indenture or the terms of the notes in their entirety. We urge you to read the forms of the indenture and the notes because the indenture and the notes, and not this description, define the rights of holders of the notes.

The notes will be issued in an aggregate principal amount of $ . The notes will mature on , . The notes will bear interest at a rate of % per year. The notes will constitute a separate series of debt securities under the indenture.

The notes will be unsecured senior debt obligations of the Operating Partnership and will rank equally with all other unsecured debt of the Operating Partnership that is not subordinated to the notes. The notes also will be effectively subordinated to the secured indebtedness of the Operating Partnership and will be effectively subordinated to the indebtedness and other liabilities of our other consolidated subsidiaries. See "Risk Factors—The effective subordination of the notes and the guarantee may reduce amounts available for payment of the notes and the guarantee" in this prospectus supplement.

CubeSmart will fully and unconditionally guarantee the due and punctual payment of principal, interest and other amounts due on the notes. The guarantee will be an unsecured and unsubordinated obligation of CubeSmart. The guarantee effectively will be subordinated to the secured indebtedness of CubeSmart. CubeSmart, however, has no material assets other than its interest in the Operating Partnership. See "Risk Factors—CubeSmart has no material assets other than its investment in the Operating Partnership" and "—The effective subordination of the notes and the guarantee may reduce amounts available for payment of the notes and the guarantee" in this prospectus supplement.

The notes will be issued only in registered form in denominations of $2,000 and integral multiples of $1,000 in excess thereof. The notes will be issued in the form of one or more global securities. See "—Book-Entry Procedures" in this prospectus supplement and "Description of the Debt Securities—Book-Entry System and Global Securities" in the accompanying prospectus. The DTC will be the depositary with respect to the notes. The notes will be issued as fully registered securities in the name of Cede & Co., DTC's nominee, and will be held by a custodian for DTC.

The defeasance and covenant defeasance provisions of the indenture will apply to the notes. The notes will not be subject to repayment at the option of any holder before maturity. In addition, the notes will not be entitled to the benefit of any sinking fund.

We reserve the right to issue additional notes, without limitation, without your consent. If we issue additional notes under the indenture, the additional notes will be identical to the notes being offered

by this prospectus supplement in all respects (except for the issue date, the public offering price and, if applicable, the first payment date, and payment of interest accruing prior to the issue date of the additional notes) so that the additional notes may be consolidated, and form a single series with, the notes offered by this prospectus supplement.

Interest on the notes will accrue from, and including, , 2019. We will make interest payments on the notes semi-annually in arrears on and of each year, beginning on , 2019, to the registered holders of such series of notes at the close of business on the immediately preceding or , as the case may be.

Interest payments in respect of the notes will equal the amount of interest accrued from, and including, the immediately preceding interest payment date in respect of which interest has been paid or duly made available for payment (or from, and including, the date of issue, if no interest has been paid or duly made available for payment with respect to the notes) to, but excluding, the applicable interest payment date or maturity date, as the case may be.

Interest on the notes will be computed on the basis of a 360-day year of twelve 30-day months.

If any interest payment date, maturity date or redemption date with respect to the notes falls on a day that is not a Business Day, the required payment of principal, Make-Whole Premium, if any, and/or interest on the notes to be redeemed will be made on the next succeeding Business Day as if made on the date on which such payment was due, and no interest will accrue on such payment for the period from and after such interest payment date, maturity date or redemption date, as the case may be, to the date of such payment on the next succeeding Business Day; provided, however, that with respect to a redemption date, if the next such succeeding Business Day falls on a day in the next succeeding calendar year from such redemption date, the required payment of principal, Make-Whole Premium, if any, and/or interest on the notes to be redeemed will be made on the Business Day immediately preceding the redemption date on which such payment was due.

The notes may be redeemed at our option, in whole, or from time to time in part prior to their maturity at the applicable redemption price listed below.

If the notes are redeemed before the Par Call Date, the notes will be redeemed at a redemption price equal to the greater of:

plus accrued and unpaid interest on the principal amount being redeemed to, but not including, the redemption date.

If the notes are redeemed on or after the Par Call Date, the notes will be redeemed at a redemption price equal to 100% of the principal amount of the notes then outstanding being redeemed, plus accrued and unpaid interest on the principal amount being redeemed to, but not including, the redemption date.

For purposes of the optional redemption provisions, the following terms have the following definitions:

"Comparable Treasury Issue" means the U.S. Treasury security selected by an Independent Investment Banker as having a maturity comparable to the remaining term of the notes to be redeemed (assuming, for this purpose, that the notes mature on the Par Call Date) (the "remaining life") that

would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such notes.

"Comparable Treasury Price" means (1) the average of five Reference Treasury Dealer Quotations for a redemption date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or (2) if the Independent Investment Banker obtains fewer than five such Reference Treasury Dealer Quotations, the average of all such quotations.

"Independent Investment Banker" means Wells Fargo Securities, LLC, Barclays Capital Inc. and Jefferies LLC or, if such firms are unwilling or unable to select the Comparable Treasury Issue, an independent investment banking institution of national standing appointed by us.

"Reference Treasury Dealer" means each of (1) Wells Fargo Securities, LLC, Barclays Capital Inc. and Jefferies LLC and their successors; provided, however, that, if any of the foregoing ceases to be a primary U.S. government securities dealer (a "primary treasury dealer"), the Operating Partnership will substitute therefor another primary treasury dealer and (2) any two other primary treasury dealers selected by the Operating Partnership after consultation with the Independent Investment Banker.

"Reference Treasury Dealer Quotations" means, with respect to each Reference Treasury Dealer and any redemption date, the average, as determined by the Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker at 5:00 p.m. (New York City time) on the third Business Day preceding such redemption date.

The Treasury Rate will be calculated by the Operating Partnership on the third Business Day preceding the date fixed for redemption.

We will provide a notice of redemption to each holder of notes to be redeemed at least 15 and not more than 60 days prior to the date fixed for redemption. Unless we default on payment of the redemption price, interest will cease to accrue on the notes or portions thereof called for redemption. If fewer than all of the notes are to be redeemed, the trustee will select, not more than 60 days prior to the redemption date, the particular notes or portions thereof for redemption from the outstanding notes not previously called by such method as the trustee deems fair and appropriate.

The Operating Partnership shall not, and shall not permit any of its Subsidiaries to, incur any Indebtedness, other than Intercompany Indebtedness, if, immediately after giving effect to the incurrence of such additional Indebtedness and the application of the proceeds thereof, the aggregate principal amount of all outstanding Indebtedness of the Operating Partnership and its Subsidiaries on a consolidated basis determined in accordance with GAAP is greater than 60% of the sum of (without duplication):

The Operating Partnership shall not, and shall not permit any of its Subsidiaries to, incur any Indebtedness if the ratio of Consolidated Income Available for Debt Service to the Annual Debt Service Charge for the four consecutive fiscal quarters most recently ended prior to the date on which such additional Indebtedness is to be incurred shall have been less than 1.5:1, on a pro forma basis after giving effect thereto and to the application of the proceeds therefrom, and calculated on the assumption that:

The Operating Partnership shall not, and shall not permit any of its Subsidiaries to, incur any Indebtedness secured by any Encumbrance upon any of the property of the Operating Partnership or

any of its Subsidiaries, whether owned at the date of the Indenture or thereafter acquired, if, immediately after giving effect to the incurrence of such additional Indebtedness secured by an Encumbrance and the application of the proceeds thereof, the aggregate principal amount of all outstanding Indebtedness of the Operating Partnership and its Subsidiaries on a consolidated basis which is secured by any Encumbrance on property of the Operating Partnership or any of its Subsidiaries is greater than 40% of the sum of (without duplication):

The Operating Partnership and its Subsidiaries may not at any time own Total Unencumbered Assets equal to less than 150% of the aggregate outstanding principal amount of the Unsecured Indebtedness of the Operating Partnership and its Subsidiaries on a consolidated basis.

For purposes of the covenants above, the following terms have the following definitions:

"Acquired Indebtedness" means Indebtedness of a Person (i) existing at the time such Person becomes a Subsidiary or (ii) assumed in connection with the acquisition of assets from such Person, in each case, other than Indebtedness incurred in connection with, or in contemplation of, such Person becoming a Subsidiary or such acquisition. Acquired Indebtedness shall be deemed to be incurred on the date of the related acquisition of assets from any Person or the date on which the acquired Person becomes a Subsidiary.

"Annual Debt Service Charge" means, for any period, the aggregate interest expense (including without limitation, the interest component of any lease of property by the Operating Partnership or any of its Subsidiaries as lessee which is reflected on the Operating Partnership's consolidated balance sheet in accordance with GAAP and letter of credit fees, commitment fees and other similar financial charges) for such period in respect of, and the amortization during such period of any original issue discount of, Indebtedness of the Operating Partnership and its Subsidiaries.

"Consolidated Income Available for Debt Service" means, for any period, Earnings from Operations of the Operating Partnership and its Subsidiaries plus amounts which have been deducted, and minus amounts which have been added, for the following (without duplication): (i) Annual Debt Service Charge of the Operating Partnership and its Subsidiaries, (ii) provision for taxes of the Operating Partnership and its Subsidiaries based on income, (iii) provisions for gains and losses on properties and depreciation and amortization, (iv) increases in deferred taxes and other non-cash items, (v) depreciation and amortization with respect to interests in joint venture and partially owned entity investments, (vi) the effect of any charge resulting from a change in accounting principles in determining Earnings from Operations for such period and (vii) amortization of deferred charges.

"Earnings from Operations" means, for any period, net income or loss of the Operating Partnership and its Subsidiaries, excluding: (i) provisions for gains and losses on sales of investments or joint ventures; (ii) provisions for gains and losses on disposition of discontinued operations;

(iii) extraordinary and non-recurring items; and (iv) impairment charges and property valuation losses, as reflected in the consolidated financial statements of the Operating Partnership and its Subsidiaries for such period determined in accordance with GAAP.

"Encumbrance" means any mortgage, lien, pledge or security interest of any kind.

"Indebtedness" means, with respect to the Operating Partnership or any of its Subsidiaries (without duplication) any indebtedness of the Operating Partnership or any of its respective Subsidiaries, (i) in respect of borrowed money, (ii) evidenced by bonds, notes, debentures or similar instruments, (iii) secured by any Encumbrance existing on property owned by the Operating Partnership or any of its Subsidiaries, (iv) consisting of letters of credit or amounts representing the balance deferred and unpaid of the purchase price of any property, except any such balance that constitutes an accrued expense or trade payable, or (v) in respect of any lease of property by the Operating Partnership or any of its Subsidiaries as lessee which is reflected on the Operating Partnership's consolidated balance sheet in accordance with GAAP, and also includes, to the extent not otherwise included, any obligation by the Operating Partnership or any of its Subsidiaries to be liable for, or to pay, as obligor, guarantor or otherwise (other than for purposes of collection in the ordinary course of business), indebtedness of another person (other than the Operating Partnership or its Subsidiaries); it being understood that indebtedness shall be deemed to be incurred by the Operating Partnership or any of its Subsidiaries whenever it or that Subsidiary creates, assumes, guarantees or otherwise becomes liable in respect thereof. Indebtedness of any Subsidiary existing prior to the time it became a Subsidiary of the Operating Partnership shall be deemed to be incurred at the time that Subsidiary becomes a Subsidiary of the Operating Partnership; and Indebtedness of a Person existing prior to a merger or consolidation of that person with the Operating Partnership or any of its Subsidiaries in which that Person is the successor to the Operating Partnership or that Subsidiary shall be deemed to be incurred upon the consummation of that merger or consolidation. Notwithstanding the preceding sentences of this definition, the term Indebtedness shall not include any indebtedness that had been the subject of an "in substance" defeasance in accordance with GAAP.

"Intercompany Indebtedness" means Indebtedness to which the only parties are the Operating Partnership, any of the Guarantors and any of their respective Subsidiaries (but only so long as such Indebtedness is held solely by any of the Operating Partnership, any of the Guarantors and any of their respective Subsidiaries) that is subordinate in right of payment to the Securities.

"Total Assets" means, as of any date, the sum of (i) the Undepreciated Real Estate Assets and (ii) all other assets of the Operating Partnership and its Subsidiaries determined in accordance with GAAP (but excluding accounts receivable and intangibles).

"Total Unencumbered Assets" means the sum of (i) those Undepreciated Real Estate Assets not subject to an Encumbrance for borrowed money and (ii) all other assets of the Operating Partnership and its Subsidiaries not subject to an Encumbrance for borrowed money, determined in accordance with GAAP (but excluding accounts receivable and intangibles); provided, however, that, in determining the Total Unencumbered Assets as a percentage of outstanding Unsecured Indebtedness, all investments by the Operating Partnership and its Subsidiaries in unconsolidated joint ventures, unconsolidated limited partnerships, unconsolidated limited liability companies and other unconsolidated entities shall be excluded from Total Unencumbered Assets to the extent that such investments would have otherwise been included.

"Undepreciated Real Estate Assets" means, as of any date, the cost (original cost plus capital improvements) of real estate assets of the Operating Partnership and its Subsidiaries on such date, before depreciation and amortization, determined on a consolidated basis in accordance with GAAP.

"Unsecured Indebtedness" means Indebtedness which is not secured by any Encumbrance upon any of the properties of the Operating Partnership or any of its Subsidiaries.

The Operating Partnership and CubeSmart may waive the application of any covenant described above at any time (whether before or after compliance is measured) if the holders of more than 50% of the principal amount of the notes then outstanding waive such compliance.

The indenture contains various covenants. See "Description of the Debt Securities—Covenants" and "—Events of Default, Notice and Waiver" in the accompanying prospectus. The covenants contained in the indenture will apply to the notes.

So long as any notes are outstanding, CubeSmart and the Operating Partnership will furnish to the trustee such information, documents and other reports as may be required by the TIA, including filing with the trustee within 15 days information, documents or reports required to be filed by the Operating Partnership with the SEC. In addition, in the event the Operating Partnership is not subject to Section 13 or 15(d) of the Exchange Act, the Operating Partnership will, within 15 days after each of the respective dates by which the Operating Partnership would have been required to file annual reports, quarterly reports and other documents with the SEC, if it were so subject:

The provisions described in the accompanying prospectus under the heading "Description of the Debt Securities—Payment of Additional Amounts" will not be applicable with respect to the notes.

We will make all payments due on the notes in immediately available funds so long as the notes are in book-entry form.

We have obtained the information in this section concerning DTC and the book-entry system and procedures from sources that we believe to be reliable, but we take no responsibility for the accuracy of this information.

The notes offered hereby will be issued as fully-registered global notes which will be deposited with, or on behalf of, DTC, and registered, at the request of DTC, in the name of Cede & Co. Beneficial interests in the global notes will be represented through book-entry accounts of financial institutions acting on behalf of beneficial owners as direct or indirect participants in DTC. Beneficial interests in the global notes will be held in denominations of $2,000 and whole multiples of $1,000 in excess thereof. Except as set forth below, the global notes may be transferred, in whole and not in part, only to another nominee of DTC or to a successor of DTC or its nominee.

We will make payments on all notes represented by a global note to the paying agent which in turn will make payment to DTC or its nominee, as the case may be, as the sole registered owner and the

sole holder of the notes represented by that global note for all purposes under the indenture. Accordingly, we, the trustee and any paying agent will have no responsibility or liability for:

DTC has advised us that its current practice is to credit participants' accounts on each payment date with payments in amounts proportionate to their respective beneficial interests in the principal amount of such global note as shown on DTC's records, upon DTC's receipt of funds and corresponding detail information. The underwriters initially will designate the accounts to be credited. Payments by participants to owners of beneficial interests in a global note will be governed by standing instructions and customary practices, as is the case with securities held for customer accounts registered in "street name," and will be the sole responsibility of those participants. Book-entry notes may be more difficult to pledge because of the lack of a physical note.

So long as DTC or its nominee is the registered owner of a global note, DTC or its nominee, as the case may be, will be considered the sole owner and holder of the notes represented by that global note for all purposes of the notes. Owners of beneficial interests in the notes will not be entitled to have notes registered in their names, will not receive or be entitled to receive physical delivery of the notes in definitive form and will not be considered owners or holders of notes under the indenture. Accordingly, each person owning a beneficial interest in a global note must rely on the procedures of DTC and, if that person is not a DTC participant, on the procedures of the participant through which that person owns its interest, to exercise any rights of a holder of notes. The laws of some jurisdictions require that certain purchasers of securities take physical delivery of the securities in certificated form. These laws may impair the ability to transfer beneficial interests in a global note. Beneficial owners may experience delays in receiving distributions on their notes since distributions initially will be made to DTC and must then be transferred through the chain of intermediaries to the beneficial owner's account.

We understand that, under existing industry practices, if we request holders to take any action, or if an owner of a beneficial interest in a global note desires to take any action which a holder is entitled to take under the indenture, then DTC would authorize the participants holding the relevant beneficial interests to take that action and those participants would authorize the beneficial owners owning through such participants to take that action or would otherwise act upon the instructions of beneficial owners owning through them.

Beneficial interests in a global note will be shown on, and transfers of those ownership interests will be effected only through, records maintained by DTC and its participants for that global note. The conveyance of notices and other communications by DTC to its participants and by its participants to owners of beneficial interests in the notes will be governed by arrangements among them, subject to any statutory or regulatory requirements in effect.

DTC has advised us that it is a limited-purpose trust company organized under the New York Banking Law, a "banking organization" within the meaning of the New York Banking Law, a member of the Federal Reserve System, a "clearing corporation" within the meaning of the New York Uniform Commercial Code and a "clearing agency" registered under the Exchange Act.

DTC holds the securities of its participants and facilitates the clearance and settlement of securities transactions among its participants in such securities through electronic book-entry changes in accounts of its participants. The electronic book-entry system eliminates the need for physical certificates. DTC's participants include securities brokers and dealers, including the underwriters, banks, trust companies, clearing corporations and certain other organizations, some of which, and/or their representatives, own DTC. Banks, brokers, dealers, trust companies and others that clear through or maintain a custodial relationship with a participant, either directly or indirectly, also have access to DTC's book-entry system. The rules applicable to DTC and its participants are on file with the SEC.

DTC has advised us that the above information with respect to DTC has been provided to its participants and other members of the financial community for informational purposes only and is not intended to serve as a representation, warranty or contract modification of any kind.

Initial settlement for the notes will be made in immediately available funds. Secondary market trading between DTC participants will occur in the ordinary way in accordance with DTC rules and will be settled in immediately available funds using DTC's Same-Day Funds Settlement System.

In the event that DTC discontinues providing its services as securities depository or ceases to be a clearing agency registered under the Exchange Act, we decide to discontinue use of the system of book-entry transfers through DTC, or an event of default with respect to the notes occurs, then the beneficial owners will be notified through the chain of intermediaries that definitive notes are available. Beneficial owners of global notes will then be entitled (1) to receive physical delivery in certificated form of definitive notes equal in principal amount to their beneficial interest and (2) to have the definitive notes registered in their names. The definitive notes will be issued in denominations of $2,000 and whole multiples of $1,000 in excess thereof. Definitive notes will be registered in the name or names of the person or persons DTC specifies in a written instruction to the registrar of the applicable series of notes. DTC may base its written instruction upon directions it receives from its participants. Thereafter, the holders of the definitive notes will be recognized as the "holders" of the notes under the indenture.

The indenture provides for the replacement of a mutilated, lost, stolen or destroyed definitive note, so long as the applicant furnishes to the Operating Partnership, CubeSmart and the trustee such security or indemnity and such evidence of ownership as they may require.

Clearstream Banking, société anonyme ("Clearstream"), is incorporated under the laws of Luxembourg as a professional depositary. Clearstream holds securities for its participating organizations ("Clearstream Participants") and facilitates the clearance and settlement of securities transactions between Clearstream Participants through electronic book-entry changes in accounts of Clearstream Participants, thereby eliminating the need for physical movement of certificates. Clearstream provides Clearstream Participants with, among other things, services for safekeeping, administration, clearance and establishment of internationally traded securities and securities lending and borrowing. Clearstream interfaces with domestic markets in several countries. As a professional depositary, Clearstream is subject to regulation by the Luxembourg Monetary Institute. Clearstream Participants are recognized financial institutions around the world, including underwriters, securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations, and may include the underwriters. Indirect access to Clearstream is also available to others, such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with a Clearstream Participant either directly or indirectly.

Distributions with respect to notes held beneficially through Clearstream will be credited to cash accounts of Clearstream Participants in accordance with its rules and procedures to the extent received by DTC for Clearstream.

Euroclear Bank S.A./N.V. ("Euroclear") was created in 1968 to hold securities for participants of Euroclear ("Euroclear Participants") and to clear and settle transactions between Euroclear Participants through simultaneous electronic book-entry delivery against payment, thereby eliminating the need for physical movement of certificates and any risk from lack of simultaneous transfers of securities and cash. Euroclear includes various other services, including securities lending and borrowing and interfaces with domestic markets in several markets in several countries. Euroclear is operated by Euroclear Bank S.A./N.V. (the "Euroclear Operator"), under contract with Euro-clear Clearance Systems S.C., a Belgian cooperative corporation (the "Cooperative"). All operations are conducted by the Euroclear Operator, and all Euroclear securities clearance accounts and Euroclear cash accounts are accounts with the Euroclear Operator, not the Cooperative. The Cooperative establishes policy for Euroclear on behalf of Euroclear Participants. Euroclear Participants include banks (including central banks), securities brokers and dealers and other professional financial intermediaries and may include the underwriters. Indirect access to Euroclear is also available to other firms that clear through or maintain a custodial relationship with a Euroclear Participant, either directly or indirectly.

The Euroclear Operator is regulated and examined by the Belgian Banking Commission.

Links have been established among DTC, Clearstream and Euroclear to facilitate the initial issuance of the notes sold outside of the United States and cross-market transfers of the notes associated with secondary market trading.

Although DTC, Clearstream and Euroclear have agreed to the procedures provided below in order to facilitate transfers, they are under no obligation to perform these procedures, and these procedures may be modified or discontinued at any time.

The information in this section concerning DTC, Clearstream and Euroclear and DTC's book-entry system has been obtained from sources that we believe to be reliable, but we take no responsibility for the accuracy of this information.

The notes, the guarantee and the indenture will be governed by, and construed in accordance with, the laws of the State of New York.

The following discussion describes the material United States federal income tax considerations relating to the purchase, ownership and disposition of the notes issued pursuant to this offering. Please see the discussion entitled "Material United States Federal Income Tax Considerations" in Exhibit 99.1 of our Annual Report on Form 10-K for the year ended December 31, 2017 for a summary of the material United States federal income tax considerations relating to the qualification and taxation of CubeSmart as a REIT, which is incorporated by reference into this prospectus supplement and supersedes the discussion under "Material Federal Income Tax Considerations" in the accompanying prospectus. The discussion below supersedes the discussion in Exhibit 99.1 under the heading "Material United States Federal Income Tax Considerations—Taxation of Holders of Debt Securities" for purposes of this offering of notes.

This discussion is not exhaustive of all possible tax considerations and does not provide a detailed discussion of any state, local or foreign tax considerations. The discussion does not address all aspects of taxation that may be relevant to particular investors in light of their personal investment or tax circumstances, or to certain types of investors that are subject to special treatment under the federal income tax laws, such as certain accrual-method taxpayers subject to special tax accounting rules under Section 451(b) of the Internal Revenue Code of 1986, as amended (the "Code"), insurance companies, regulated investment companies, REITs, tax-exempt organizations (except to the limited extent discussed below under "Taxation of Tax-Exempt Holders"), financial institutions or broker-dealers, non-U.S. individuals and foreign corporations (except to the limited extent discussed below under "—Taxation of Non-U.S. Holders") and other persons subject to special tax rules. This summary deals only with investors who hold their notes as "capital assets" within the meaning of Section 1221 of the Code. This discussion is not intended to be, and should not be construed as, tax advice.

The information in this summary is based on the Code, current, temporary and proposed Treasury regulations, the legislative history of the Code, current administrative interpretations and practices of the Internal Revenue Service (the "IRS"), including its practices and policies as endorsed in private letter rulings, which are not binding on the IRS, and existing court decisions. Future legislation, regulations, administrative interpretations and court decisions could change current law or adversely affect existing interpretations of current law. Any change could apply retroactively. We have not obtained any rulings from the IRS concerning the tax treatment of the matters discussed in this summary. Therefore, it is possible that the IRS could challenge the statements in this summary, which do not bind the IRS or the courts, and that a court could agree with the IRS.

We urge you to consult your own tax advisor regarding the specific tax consequences to you of ownership of the notes and of CubeSmart's election to be taxed as a REIT. Specifically, you should consult your own tax advisor regarding the federal, state, local, foreign, and other tax consequences of such ownership and election, and regarding potential changes in applicable tax laws.

As used herein, a "U.S. Holder" means a beneficial owner of notes who is, for United States federal income tax purposes:

If a partnership, including any entity that is treated as a partnership for federal income tax purposes, holds notes, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. If you are a partner of a partnership holding notes, you should consult your tax advisor regarding the consequences of the ownership and disposition of notes by the partnership.

In certain circumstances, we may be obligated to pay amounts in excess of the stated interest or principal on the notes or may pay amounts at times other than on the scheduled interest payment dates or the maturity date (see "Description of the Notes and the Guarantee—Optional Redemption"). These potential payments may implicate the provisions of Treasury Regulations relating to "contingent payment debt instruments." Although the matter is not free from doubt, we intend to take the position that the possibility of the foregoing payments does not result in the notes being treated as contingent payment debt instruments. Our position is binding on a holder subject to U.S. federal income taxation unless the holder discloses its contrary position to the IRS in accordance with applicable Treasury Regulations. Our position is not, however, binding on the IRS, and if the IRS were to successfully challenge this position, a holder might be required to accrue ordinary interest income on the notes in an amount greater than, and with timing different from the timing described herein with respect to, the stated interest and to treat any gain realized on a taxable disposition of the notes as ordinary interest income rather than capital gain. The remainder of this discussion assumes that the notes will not be treated as contingent payment debt instruments.

Pursuant to the Tax Cuts and Jobs Act, for taxable years beginning after December 31, 2017 (or, for instruments issued with OID (as defined below), for taxable years beginning after December 31, 2018), an accrual method taxpayer that reports revenues on an applicable financial statement generally must recognize income for U.S. federal income tax purposes no later than the taxable year in which such income is taken into account as revenue in an applicable financial statement of the taxpayer. To the extent this rule is inconsistent with the rules described in the subsequent discussion, this rule supersedes such discussion. Thus, this rule could potentially require such a taxpayer to recognize income for U.S. federal income tax purposes with respect to the debt securities prior to the time such income would be recognized pursuant to the rules described in the subsequent discussion. It is currently not clear how this rule would apply to debt instruments with OID and market discount. You should consult your tax advisors regarding the potential applicability of these rules to your investment in the debt securities.

Interest. The stated interest on the notes generally will be taxable to a U.S. Holder as ordinary income at the time that it is paid or accrued, in accordance with the U.S. Holder's method of accounting for United States federal income tax purposes.

In general, if the terms of a debt instrument entitle a holder to receive payments other than fixed periodic interest that exceeds the issue price of the instrument, the holder may be required to recognize additional interest as "original issue discount," sometimes referred to as "OID." The notes are not expected to be issued with OID for U.S. federal income tax purposes. The notes will be treated as issued with OID if their principal amount exceeds their issue price by at least a de minimis amount (0.25% of the principal amount multiplied by the number of complete years from the issue date of the notes until their maturity). If the notes are treated as issued with OID pursuant to these rules, a U.S.

Holder would be required to include OID in income as it accrues based on a constant yield to maturity method before the receipt of corresponding cash payments. The remainder of this discussion assumes that the notes are issued with less than a de minimis amount of OID.

Market Discount. If you purchase notes after original issuance for an amount that is less than their stated redemption price at maturity, the amount of the difference will be treated as "market discount" for United States federal income tax purposes, unless that difference is less than a specified de minimis amount. Under the market discount rules, you will be required to treat any principal payment on, or any gain on the sale, exchange, retirement or other disposition of, the notes as ordinary income to the extent of the market discount that you have not previously included in income and are treated as having accrued on the notes at the time of their payment or disposition. In addition, you may be required to defer, until the maturity of the notes or their earlier disposition in a taxable transaction, the deduction of all or a portion of the interest expense on any indebtedness attributable to the notes. You may elect, on a debt security-by-debt security basis, to deduct the deferred interest expense in a tax year prior to the year of disposition. You should consult your own tax advisors before making this election.

Any market discount will be considered to accrue ratably during the period from the date of acquisition to the maturity date of the notes, unless you elect to accrue on a constant interest method. You may elect to include market discount in income currently as it accrues, on either a ratable or constant interest method, in which case the rule described above regarding deferral of interest deductions will not apply. Your election to include market discount in income currently, once made, applies to all market discount obligations acquired by you on or after the first taxable year to which your election applies and may not be revoked without the consent of the IRS. You should consult your own tax advisor before making this election.

Acquisition Premium and Amortizable Bond Premium. If you purchase notes for an amount in excess of the sum of all amounts payable on those notes after the purchase date other than qualified stated interest, you will be considered to have purchased those notes at a "premium." You generally may elect to amortize the premium over the remaining term of those notes on a constant yield method as an offset to interest when includible in income under your regular accounting method. In the case of notes that provide for alternative payment schedules, bond premium is calculated by assuming that (a) you will exercise or not exercise options in a manner that maximizes your yield, and (b) we will exercise or not exercise options in a manner that minimizes your yield (except that we will be assumed to exercise call options in a manner that maximizes your yield). If you do not elect to amortize bond premium, that premium will decrease the gain or increase the loss you would otherwise recognize on disposition of the note. Your election to amortize premium on a constant yield method will also apply to all debt obligations held or subsequently acquired by you on or after the first day of the first taxable year to which the election applies. You may not revoke the election without the consent of the IRS. You should consult your own tax advisor before making this election.

Sale, Exchange and Retirement of Notes. A U.S. Holder of notes will recognize gain or loss upon the sale, exchange, retirement, redemption or other taxable disposition of such notes in an amount equal to the difference between:

A U.S. Holder's adjusted tax basis in a note generally will equal the cost of the note to such holder (A) increased by the amount of accrued market discount (if any) previously included in income

by such holder and (B) decreased by the amount of (1) any payments other than qualified stated interest payments and (2) any amortizable bond premium taken by the holder.

Any gain or loss recognized will generally be capital gain or loss, and such capital gain or loss will generally be long-term capital gain or loss if the note has been held by the U.S. Holder for more than one year. Long-term capital gain for non-corporate taxpayers is subject to reduced rates of United States federal income taxation (20% maximum federal rate). The deductibility of capital losses is subject to certain limitations.

If a U.S. Holder recognizes a loss upon a subsequent disposition of notes in an amount that exceeds a prescribed threshold, it is possible that the provisions of Treasury Regulations involving "reportable transactions" could apply, with a resulting requirement to separately disclose the loss generating transactions to the IRS. While these regulations are directed towards "tax shelters," they are written broadly, and apply to transactions that would not typically be considered tax shelters. Significant penalties apply for failure to comply with these requirements. You should consult your tax advisors concerning any possible disclosure obligation with respect to the receipt or disposition of notes, or transactions that might be undertaken directly or indirectly by us. Moreover, you should be aware that we and other participants in transactions involving us (including our advisors) might be subject to disclosure or other requirements pursuant to these regulations.

Unearned Income Medicare Contribution. A tax of 3.8% is imposed on certain "net investment income" (or "undistributed net investment income," in the case of estates and trusts) received by certain taxpayers with adjusted gross income above certain threshold amounts. "Net investment income" as defined for United States federal Medicare contribution purposes generally includes interest payments and gain recognized from the sale, exchange, redemption or other taxable disposition of the notes. Tax-exempt trusts, which are not subject to income taxes generally, and foreign individuals will not be subject to this tax. U.S. holders should consult their own tax advisors regarding the effect, if any, of this tax on their ownership and disposition of the notes.

Assuming the notes are debt for tax purposes, interest income accrued on the notes should not constitute unrelated business taxable income to a tax-exempt holder. As a result, a tax-exempt holder generally should not be subject to United States federal income tax on the interest income accruing on the notes. Similarly, any gain recognized by the tax-exempt holder in connection with a sale of the notes generally should not be unrelated business taxable income. However, if a tax-exempt holder were to finance its acquisition of the notes with debt, a portion of the interest income and gain attributable to the notes would constitute unrelated business taxable income pursuant to the "debt-financed property" rules. Tax-exempt holders should consult their own counsel to determine the potential tax consequences of an investment in the notes.

The term "non-U.S. Holder" means a holder of notes that is not a U.S. Holder or a partnership (or an entity treated as a partnership for United States federal income tax purposes). The rules governing United States federal income taxation of non-U.S. Holders are complex. This section is only a summary of such rules. We urge non-U.S. Holders to consult their own tax advisors to determine the impact of federal, state, local and foreign income tax laws on ownership of notes, including any reporting requirements.

Interest. Subject to the discussion below concerning backup withholding and the legislation commonly referred to as the Foreign Account Tax Compliance Act ("FATCA"), interest paid to a

non-U.S. Holder of notes will not be subject to United States federal income or withholding tax under the "portfolio interest exception," provided that:

A payment of interest to a non-U.S. Holder that does not qualify for the portfolio interest exception and that is not effectively connected to a United States trade or business will be subject to United States federal withholding tax at a rate of 30%, unless a United States income tax treaty applies to reduce or eliminate withholding.

A non-U.S. Holder will generally be subject to tax in the same manner as a U.S. Holder with respect to payments of interest if such payments are effectively connected with the conduct of a trade or business by the non-U.S. Holder in the United States and, if an applicable tax treaty provides, such gain is attributable to a United States permanent establishment maintained by the non-U.S. Holder. In some circumstances, such effectively connected income received by a non-U.S. Holder which is a corporation may be subject to an additional "branch profits tax" at a 30% base rate or, if applicable, a lower treaty rate.

To claim the benefit of a lower treaty rate or to claim exemption from withholding because the income is effectively connected with a United States trade or business, the non-U.S. Holder must provide a properly executed IRS Form W-8BEN, IRS Form W-8BEN-E or IRS Form W-8ECI, or a suitable substitute form, as applicable, prior to the payment of interest. Such certificate must contain, among other information, the name and address of the non-U.S. Holder.

Non-U.S. Holders are urged to consult their own tax advisors regarding applicable income tax treaties, which may provide different rules.

Sale or Retirement of Notes. A non-U.S. Holder generally will not be subject to United States federal income tax or withholding tax on gain realized on the sale, exchange or redemption of notes unless:

If the non-U.S. Holder is an individual present in the United States for 183 days or more in the taxable year of the disposition, such gain (which may be offset by certain U.S. source losses) generally will be subject to a 30% tax (or lower treaty rate, if applicable). Except to the extent that an applicable tax treaty provides otherwise, a non-U.S. Holder will generally be subject to tax in the same manner as a U.S. Holder with respect to gain realized on the sale, exchange or redemption of notes if such gain is effectively connected with the conduct of a trade or business by the non-U.S. Holder in the United States and, if an applicable tax treaty provides, such gain is attributable to a United States permanent establishment maintained by the non-U.S. Holder. In certain circumstances, a non-U.S. Holder that is a corporation will be subject to an additional "branch profits tax" at a 30% rate or, if applicable, a lower treaty rate on such income.

To the extent that the amount realized on any sale, exchange, redemption or other taxable disposition of the notes is attributable to accrued but unpaid interest, such amount will be treated as interest for United States federal income tax purposes.

United States Federal Estate Tax. Your estate will not be subject to United States federal estate tax on the notes beneficially owned by you at the time of your death, provided that any payment to you on the notes would be eligible for exemption from the 30% United States federal withholding tax under the "portfolio interest" rule described above, without regard to the certification requirement.

Certain U.S. Holders may be subject to information reporting requirements on payments of principal and interest on notes and payments of the proceeds of the sale, exchange, or redemption of notes, and backup withholding, currently imposed at a rate of 24%, may apply to such payment if the U.S. Holder:

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules from a payment to a U.S. Holder will be allowed as a refund or a credit against such non-U.S. Holder's United States federal income tax liability, provided that the requisite procedures are followed.

U.S. Holders of notes are urged to consult their tax advisors regarding their qualification for exemption from backup withholding and the procedure for obtaining such an exemption, if applicable.

A non-U.S. Holder is generally not subject to backup withholding with respect to payments of interest on notes if it certifies as to its status as a non-U.S. Holder under penalties of perjury or if it otherwise establishes an exemption, provided that neither we nor our paying agent has actual knowledge or reason to know that the non-U.S. Holder is a United States person or that the conditions of any other exemptions are not, in fact, satisfied. Information reporting requirements, however, will apply to payments of interest to non-U.S. Holders where such interest is subject to withholding or

exempt from United States withholding tax pursuant to a tax treaty. Copies of these information returns may also be made available under the provisions of a specific treaty or agreement to the tax authorities of the country in which the non-U.S. Holder resides.

The payment of the proceeds from the disposition of notes to or through the United States office of any broker, United States or foreign, will be subject to information reporting and possible backup withholding unless the owner certifies as to its non-United States status under penalties of perjury or otherwise establishes an exemption, provided that the broker does not have actual knowledge or reason to know that the non-U.S. Holder is a United States person or that the conditions of any other exemption are not, in fact, satisfied.

The payment of the proceeds from the disposition of notes to or through a non-United States office of a non-United States broker that is not a "United States related person" generally will not be subject to information reporting or backup withholding. For this purpose, a "United States related person" is:

In the case of the payment of proceeds from the disposition of notes to or through a non-United States office of a broker that is either a United States person or a United States related person, the payment may be subject to information reporting unless the broker has documentary evidence in its files that the owner is a non-U.S. Holder and the broker has no knowledge or reason to know to the contrary. Backup withholding will not apply to payments made through foreign offices of a broker that is a United States person or a United States related person, absent actual knowledge that the payee is a United States person.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules from a payment to a non-U.S. Holder will be allowed as a refund or a credit against such non-U.S. Holder's United States federal income tax liability, provided that the requisite procedures are followed.

Non-U.S. Holders of notes are urged to consult their tax advisors regarding their qualification for exemption from backup withholding and the procedure for obtaining such an exemption, if applicable.

Payments of interest to a non-U.S. holder will be subject to a 30% withholding tax if the non-U.S. holder fails to provide the withholding agent with documentation sufficient to show that it is compliant with FATCA. Generally such documentation is provided on an executed IRS Form W-8BEN or IRS Form W-8BEN-E, as applicable. If interest is subject to the 30% tax under FATCA, it will not be subject to the 30% tax described above under "Taxation of Non-U.S. Holders—Interest." Based upon proposed Treasury regulations, which may be relied upon by taxpayers until the final Treasury regulations are issued, the FATCA withholding that was to be effective on January 1, 2019 with respect to payments of the gross proceeds no longer applies.

Subject to the terms and conditions set forth in an underwriting agreement, we have agreed to sell to the underwriters named below, and the underwriters, for whom Wells Fargo Securities, LLC, Barclays Capital Inc. and Jefferies LLC are acting as the joint book-running managers and representatives, have severally agreed to purchase from us, the principal amount of notes appearing below:

The underwriting agreement provides that the obligations of the several underwriters are subject to various conditions, including approval of legal matters by counsel. The notes are offered by the underwriters, subject to prior sale, when, as and if issued to and accepted by them. The underwriters reserve the right to withdraw, cancel or modify the offer and to reject orders in whole or in part.

The underwriting agreement provides that the underwriters are obligated to purchase all of the notes offered by this prospectus supplement and the accompanying prospectus if any are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the non-defaulting underwriters may be increased or the underwriting agreement may be terminated.

Notes sold in this offering by the underwriters to the public will initially be offered at the public offering price set forth on the cover of this prospectus supplement. Any notes sold by the underwriters to securities dealers may be sold at a discount from the public offering price of up to % of the principal amount of the notes. Any such securities dealers may resell any notes purchased from the underwriters to certain other brokers or dealers at a discount from the public offering price of up to % of the principal amount of the notes. After the notes are released for sale, the underwriters may change the offering price and the other selling terms.

We estimate that the expenses of this offering payable by us, not including the underwriting discounts, will be approximately $500,000.

The notes are a new issue of securities with no established trading market. We do not intend to apply for listing of the notes on any securities exchange or for quotation on any automated quotation system. The underwriters may make a market in the notes after the completion of this offering but will not be obliged to do so and may discontinue any market-making activities at any time without notice. No assurance can be given as to the liquidity of any trading market for the notes or that an active public market for the notes will develop. If an active public market for the notes does not develop, the market price and liquidity of the notes may be adversely affected.

The underwriting agreement provides that we will indemnify the underwriters against specified liabilities in connection with this offering, including liabilities under the Securities Act, or contribute to payments that the underwriters may be required to make in respect of those liabilities.

Until the distribution of the notes is completed, SEC rules may limit the ability of the underwriters to bid for or purchase the notes. However, the representatives may engage in transactions that stabilize the price of the notes, such as bids or purchases to peg, fix or maintain that price.

If the underwriters create a short position in the notes in connection with this offering, i.e., if they sell more notes than are listed on the cover page of this prospectus supplement, the underwriters may reduce that short position by purchasing notes in the open market. Purchases of notes to stabilize the per note price or to reduce a short position may cause the price of the notes to be higher than it might be in the absence of those purchases.

Neither we nor the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of the notes. In addition, neither we nor the underwriters make any representation that the underwriters will engage in those transactions or that those transactions, once commenced, will not be discontinued without notice.

The underwriters and/or their respective affiliates have in the past provided and may in the future provide various financial advisory, investment banking, commercial banking and other financial services to us, for which they have received and in the future may receive compensation.

In addition, in the ordinary course of their various business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers and such investment and securities activities may involve securities or instruments of ours or our affiliates. Certain of the underwriters and their affiliates that have a lending relationship with us may also choose to hedge their credit exposure to us consistent with their customary risk management policies. Typically, such underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. The underwriters or their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may at any time hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Wells Fargo Securities, LLC and Barclays Capital Inc. and certain of the other underwriters and/or their affiliates act as lenders and/or agents under our $700 million unsecured credit facility and our unsecured term loans. Wells Fargo Securities, LLC and certain of the other underwriters and/or their affiliates also act as lenders under mortgages on certain of our properties. As described in "Use of Proceeds" in this prospectus supplement, we intend to use the net proceeds from this offering of notes to repay $200.0 million of outstanding indebtedness incurred under the unsecured term loan portion of our credit facility maturing in January 2019 and for working capital and other general corporate purposes, which may include repayment or repurchase of other indebtedness. To the extent that we use

the net proceeds from this offering to repay indebtedness under the unsecured term loan portion of our credit facility or any other amounts we have borrowed or may borrow in the future under our credit facility, term loans or any mortgage loans, those lenders will receive their pro rata portion of any of the proceeds from this offering that we use to repay any such amounts. Because more than 5% of the net proceeds from this offering will be used to repay indebtedness under the unsecured term loan portion of our credit facility, a "conflict of interest" under Rule 5121 of the Financial Industry Regulatory Authority, Inc. ("FINRA"). Because the notes offered hereby are investment grade rated, no "qualified independent underwriter" is required to be appointed in connection with this offering. However, as required by FINRA Rule 5121, no sale of the notes offered hereby will be made by the affected underwriter to an account over which it exercises discretionary authority without the prior written approval of the customer. In addition, Wells Fargo Securities, LLC, Barclays Capital Inc. and Jefferies LLC and certain of the other underwriters also serve as sales agents under CubeSmart's "at-the-market" equity issuance program.

This prospectus supplement is only being distributed to, and are only directed at, (i) persons who are outside the United Kingdom or (ii) investment professionals falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (the "Order") or (iii) high net worth entities, and other persons to whom it may lawfully be communicated, falling within Article 49(2)(a) to (d) of the Order (each such person being referred to as a "relevant person"). The notes are only available to, and any invitation, offer or agreement to subscribe, purchase or otherwise acquire the notes will be engaged in only with, relevant persons. Any person who is not a relevant person should not act or rely on this prospectus supplement or any of its contents.

No placement document, prospectus, product disclosure statement or other disclosure document has been or will be lodged with the Australian Securities and Investments Commission ("ASIC") in relation to this offering. This prospectus supplement and the accompanying prospectus do not constitute a prospectus, product disclosure statement or other disclosure document under the Corporations Act 2001 (the "Corporations Act"), and do not purport to include the information required for a prospectus, product disclosure statement or other disclosure document under the Corporations Act.

Any offer in Australia of the notes may only be made to persons (the "Exempt Investors") who are "sophisticated investors" (within the meaning of section 708(8) of the Corporations Act), "professional investors" (within the meaning of section 708(11) of the Corporations Act) or otherwise pursuant to one or more exemptions contained in section 708 of the Corporations Act so that it is lawful to offer the notes without disclosure to investors under Chapter 6D of the Corporations Act.

The notes applied for by Exempt Investors in Australia must not be offered for sale in Australia in the period of 12 months after the date of allotment under this offering, except in circumstances where

disclosure to investors under Chapter 6D of the Corporations Act would not be required pursuant to an exemption under section 708 of the Corporations Act or otherwise or where the offer is pursuant to a disclosure document which complies with Chapter 6D of the Corporations Act. Any person acquiring notes must observe such Australian on-sale restrictions.

This prospectus supplement and the accompanying prospectus contain general information only and do not take account of the investment objectives, financial situation or particular needs of any particular person. This prospectus supplement and the accompanying prospectus do not contain any securities recommendations or financial product advice. Before making an investment decision, investors need to consider whether the information in this prospectus supplement and the accompanying prospectus is appropriate to their needs, objectives and circumstances, and, if necessary, seek expert advice on those matters.

Notice to Prospective Investors in the Dubai International Financial Centre

This prospectus supplement and the accompanying prospectus relate to an Exempt Offer in accordance with the Offered Securities Rules of the Dubai Financial Services Authority ("DFSA"). This prospectus supplement and the accompanying prospectus is intended for distribution only to persons of a type specified in the Offered Securities Rules of the DFSA. It must not be delivered to, or relied on by, any other person. The DFSA has no responsibility for reviewing or verifying any documents in connection with Exempt Offers. The DFSA has not approved this prospectus supplement or the accompanying prospectus nor taken steps to verify the information set forth herein and has no responsibility for the prospectus supplement and the accompanying prospectus. The may be illiquid and/or subject to restrictions on their resale. Prospective purchasers of the notes should conduct their own due diligence on the notes. If you do not understand the contents of this prospectus supplement and the accompanying prospectus you should consult an authorized financial advisor.

The contents of this prospectus supplement and the accompanying prospectus have not been reviewed or approved by any regulatory authority in Hong Kong. This prospectus supplement and the accompanying prospectus do not constitute an offer or invitation to the public in Hong Kong to acquire the notes. Accordingly, (i) no person has offered or sold or will offer or sell in Hong Kong, by means of any document, any notes other than (a) to "professional investors" (as such term is defined in the Securities and Futures Ordinance (Cap. 571) of Hong Kong) (the "SFO") and the any rules made under the SFO) or (b) in other circumstances which do not result in this prospectus supplement and/or the accompanying prospectus being a "prospectus" as defined in the Companies (Winding Up and Miscellaneous Provisions) Ordinance (Cap. 32) of Hong Kong (the "C(WUMP)O"), or which do not constitute an offer to the public within the meaning of the C(WUMP)O; and (ii) no person has issued or had in its possession for the purposes of issue, or will issue or have in its possession for the purposes of issue, whether in Hong Kong or elsewhere, any advertisement, invitation or document relating to the notes, which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to notes which are or are intended to be disposed of only to persons outside Hong Kong or only to "professional investors" as defined in the SFO and any rules made under the SFO. You are advised to exercise caution in relation to this offering. If you are in any doubt about the contents of this prospectus supplement and/or the accompanying prospectus, you should obtain independent professional advice.

This prospectus supplement and the accompanying prospectus have not been registered as a prospectus under the Securities and Futures Act, Chapter 289 of Singapore (the "SFA") by the

Monetary Authority of Singapore, and the offer of the notes in Singapore is made primarily pursuant to the exemptions under Sections 274 and 275 of the SFA. Accordingly, this prospectus supplement and the accompanying prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase of the notes may not be circulated or distributed, nor may the notes be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to any person in Singapore other than (i) to an institutional investor (as defined under Section 4A of the SFA) (an "Institutional Investor") pursuant to Section 274 of the SFA, (ii) to an accredited investor (as defined under Section 4A of the SFA) (an "Accredited Investor") or other relevant person (as defined in Section 275(2) of the SFA) (a "Relevant Person") and pursuant to Section 275(1) of the SFA, or to any person pursuant to an offer referred to in Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA, or (iii) otherwise pursuant to, and in accordance with, the conditions of any other applicable exemption or provision of the SFA.

It is a condition of this offering that where the notes are subscribed for or acquired pursuant to an offer made in reliance on Section 275 of the SFA by a Relevant Person which is:

securities or securities-based derivatives (each as defined in Section 2(1) of the SFA) of that corporation or the beneficiaries' rights and interest (howsoever described) in that trust shall not be transferred within 6 months after that corporation or that trust has subscribed for or acquired the notes except:

Singapore Securities and Futures Act Product Classification—Solely for the purposes of its obligations pursuant to Sections 309(B)(1)(a) and 309(B)(1)(c) of the SFA, the Operating Partnership has determined, and hereby notifies all relevant persons (as defined in Section 309A of the SFA) that the notes are "prescribed capital markets products" (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and "Excluded Investment Products" (as defined in MAS Notice SFA 04-N12: Notice on the Sale of Investment Products and MAS Notice FAA-N16: Notice on Recommendations on Investment Products).

The Operating Partnership has not and will not register with the Swiss Financial Market Supervisory Authority ("FINMA") as a foreign collective investment scheme pursuant to Article 119 of the Federal Act on Collective Investment Scheme of 23 June 2006, as amended ("CISA"), and accordingly the notes have not and will not be approved, and may not be licenseable, with FINMA. Therefore, the notes have not been authorized for distribution by FINMA as a foreign collective investment scheme pursuant to Article 119 CISA and the notes may not be offered to the public (as this term is defined in Article 3 CISA) in or from Switzerland. The notes may solely be offered to

"qualified investors," as this term is defined in Article 10 CISA, and in the circumstances set out in Article 3 of the Ordinance on Collective Investment Scheme of 22 November 2006, as amended ("CISO"), such that there is no public offer. Investors, however, do not benefit from protection under CISA or CISO or supervision by FINMA. This prospectus supplement and the accompany prospectus and any other materials relating to the notes are strictly personal and confidential to each offeree and do not constitute an offer to any other person. This prospectus supplement and the accompany prospectus may only be used by those qualified investors to whom they have been handed out in connection with this offering and may neither directly or indirectly be distributed or made available to any person or entity other than its recipients. They may not be used in connection with any other offer and shall in particular not be copied and/or distributed to the public in Switzerland or from Switzerland. This prospectus supplement and the accompany prospectus do not constitute an issue prospectus as that term is understood pursuant to Article 652a and/or 1156 of the Swiss Federal Code of Obligations. The Operating Partnership has not applied for a listing of the notes on the SIX Swiss Exchange or any other regulated notes market in Switzerland, and consequently, the information presented in this prospectus supplement and the accompany prospectus does not necessarily comply with the information standards set out in the listing rules of the SIX Swiss Exchange and corresponding prospectus schemes annexed to the listing rules of the SIX Swiss Exchange.

The validity of the notes and the guarantee will be passed upon for CubeSmart, L.P. and CubeSmart by Pepper Hamilton LLP. Certain legal matters in connection with this offering will be passed upon for the underwriters by Vinson & Elkins L.L.P.

The consolidated financial statements of CubeSmart and CubeSmart, L.P. as of December 31, 2017 and 2016, and for each of the years in the three-year period ended December 31, 2017, and the related notes and financial statement schedule III (collectively, the consolidated financial statements), and management's assessment of the effectiveness of internal control over financial reporting as of December 31, 2017 have been incorporated by reference herein in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

We incorporate information into this prospectus supplement and the accompanying prospectus by reference, which means that we disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is deemed to be part of this prospectus supplement and the accompanying prospectus, except to the extent superseded by information contained herein or by information contained in documents filed with the SEC after the date of this prospectus supplement. This prospectus supplement and the accompanying prospectus incorporate by reference the documents set forth below that have been previously filed with the SEC (other than, in each case, documents or information deemed to have been "furnished" and not "filed" in accordance with SEC rules):

We also incorporate by reference into this prospectus supplement and the accompanying prospectus additional documents that we may file with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act, from the date of this prospectus supplement until all of the securities offered by this prospectus supplement have been sold or we otherwise terminate the offering of these securities; provided, however, that we are not incorporating by reference any additional documents or information "furnished" and not "filed" with the SEC. You may obtain copies of any of these filings by contacting us at the following address and phone number or as described in this prospectus supplement under the section "Where You Can Find More Information." Documents incorporated by reference are available from us without charge, excluding all exhibits unless an exhibit has been specifically incorporated by reference into this prospectus supplement or the accompanying prospectus, by requesting them in writing, by telephone or via the Internet at:

CubeSmart
Attention: Investor Relations
5 Old Lancaster Road
Malvern, PA 19355
Phone: (610) 535-5000

We are subject to the informational requirements of the Exchange Act. Accordingly, we file current, quarterly and annual reports, proxy statements and other information with the SEC. Our SEC filings also are available to the public at the Internet website maintained by the SEC at www.sec.gov and from commercial document retrieval services.

We also make available free of charge through our website our filings with the SEC, including our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, definitive proxy statements and Section 16 reports on Forms 3, 4 and 5, as soon as reasonably practicable after we electronically file such reports or amendments with, or furnish them to, the SEC. Our Internet website address is www.cubesmart.com. The information located on, or hyperlinked or otherwise connected to, our website is not, and shall not be deemed to be, a part of this prospectus supplement, the accompanying prospectus or incorporated into any other filings that we make with the SEC. You may also inspect the information that we file with the NYSE, at the offices of the NYSE located at 11 Wall Street, New York, New York 10005.

We have filed with the SEC a registration statement on Form S-3 (Registration File No. 333-216768) covering the notes offered by this prospectus supplement and the accompanying prospectus. You should be aware that this prospectus supplement and accompanying prospectus do not contain all of the information contained or incorporated by reference in that registration statement and its exhibits and schedules. You may inspect and obtain the registration statement, including exhibits, schedules, reports and other information that we have filed with the SEC, as described in the two preceding paragraphs. Statements contained in this prospectus supplement concerning the contents of any document we refer you to are not necessarily complete and in each instance we refer you to the applicable document filed with the SEC for more complete information.

Common Shares
Preferred Shares
Depositary Shares
Subscription Rights
Warrants
Guarantees

CubeSmart may from time to time offer, in one or more classes or series, separately or together, and in amounts, at prices and on terms to be set forth in one or more supplements to this prospectus, the following securities:

CubeSmart, L.P. may from time to time offer, in one or more classes or series, separately or together, and in amounts, at prices and on terms to be set forth in one or more supplements to this prospectus, including any conversion terms, its debt securities. CubeSmart will unconditionally guarantee the payment obligations of the debt securities of CubeSmart, L.P.

Selling securityholders may offer and sell common shares from time to time in one or more offerings, at prices and on terms to be set forth in one or more supplements to this prospectus. We will not receive any proceeds from the sale of common shares by any selling securityholders.

We refer to the common shares, preferred shares, depositary shares, subscription rights, warrants and guarantees of CubeSmart, together with the debt securities of CubeSmart, L.P. collectively as the "securities."

The common shares of CubeSmart are listed on the New York Stock Exchange, or NYSE, under the symbol "CUBE."

Investing in the securities involves risks that are discussed on page 4 of this prospectus. You should carefully read and consider the information in this prospectus, the applicable prospectus supplement and the risk factors included in the applicable prospectus supplement and/or in our periodic reports and other information that we file with the Securities and Exchange Commission before investing in the securities.

Neither the Securities and Exchange Commission nor any state securities regulators have approved or disapproved these securities, or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

You should rely only on the information provided or incorporated by reference into this prospectus, any applicable prospectus supplement or any applicable free writing prospectus. Neither we nor any selling securityholder have authorized anyone to provide you with different or additional information. This prospectus does not constitute an offer to sell or a solicitation of an offer to buy by anyone in any jurisdiction in which such offer to sell is not authorized, or in which the person is not qualified to do so or to any person to whom it is unlawful to make such offer or solicitation. You should not assume that the information included in this prospectus or any prospectus supplement is accurate as of any date other than the date on its respective cover, and that any information incorporated by reference is accurate as of any date other than the date of the incorporated document. Our business, financial condition, results of operations and prospects may have changed since those dates.

This prospectus is part of a universal shelf registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or the SEC, under the Securities Act of 1933, as amended, or the Securities Act. To the extent required for any offer and sale, a prospectus supplement will set forth the type and number of securities being offered, the offering price, the names of any underwriters, dealers, brokers or agents and the applicable sales commission or discount. The prospectus supplement may also add, update or change information contained in this prospectus. You should read carefully the entire prospectus and any prospectus supplement, as well as the documents incorporated by reference into this prospectus and/or any prospectus supplement, before making an investment decision.

Under the shelf registration statement, CubeSmart may sell any combination of common shares, preferred shares, depositary shares, subscription rights and warrants in one or more offerings, and CubeSmart, L.P. may sell debt securities of various terms in one or more offerings. In addition, under this shelf registration statement, persons who have acquired common shares from us may resell these common shares from time to time. Any such persons will be named in a prospectus supplement to this prospectus as and to the extent required by SEC rules. We will not receive any proceeds from the resale by any such selling securityholders of common shares.

This prospectus and any accompanying prospectus supplement do not contain all of the information included in the registration statement. For further information, we refer you to the registration statement, including the exhibits. Statements contained in this prospectus and any accompanying prospectus supplement about the provisions or contents of any agreement or other document are not necessarily complete. If the rules and regulations of the SEC require that such agreement or document be filed as an exhibit to the registration statement, please see such agreement or document for a complete description of these matters.

As used in this prospectus and the registration statement on Form S-3 of which this prospectus is a part, unless the context otherwise requires, references to "CubeSmart" refer to CubeSmart, a Maryland real estate investment trust, or "REIT"; references to the "Operating Partnership" refer to CubeSmart, L.P., a Delaware limited partnership; and references to "we," "us," "our" or similar expressions refer collectively to CubeSmart and its consolidated subsidiaries (including the Operating Partnership).

We are subject to the informational requirements of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Accordingly, we file current, quarterly and annual reports, proxy statements and other information with the SEC. You may read and copy these reports, proxy statements and other information at the SEC's Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. Please call 1-800-SEC-0330 for further information on the operation of the SEC's Public Reference Room. Our SEC filings also are available to the public at the Internet website maintained by the SEC at www.sec.gov and from commercial document retrieval services.

We also make available free of charge through our website the filings made by CubeSmart and the Operating Partnership with the SEC, including CubeSmart's and the Operating Partnership's annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, and CubeSmart's definitive proxy statements and Section 16 reports on Forms 3, 4 and 5, as soon as reasonably practicable after we electronically file such reports or amendments with, or furnish them to, the SEC. Our Internet website address is www.cubesmart.com. The information located on, or hyperlinked or otherwise connected to, our website is not, and shall not be deemed to be, a part of this prospectus or incorporated into any other filings that we make with the SEC. You may also inspect the information that we file with the NYSE, at the offices of the NYSE located at 20 Broad Street, New York, New York 10005.

We incorporate information into this prospectus by reference, which means that we disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is deemed to be part of this prospectus, and subsequent information that we file with the SEC will automatically update and supersede that information. Any statement contained in a previously filed document incorporated by reference will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus modifies or replaces that statement. This prospectus incorporates by reference the documents set forth below that have been previously filed with the SEC (other than, in each case, documents or information deemed to have been "furnished" and not "filed" in accordance with SEC rules):

We also incorporate by reference into this prospectus additional documents that we may file with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act, from the date of this prospectus until all of the securities offered by this prospectus have been sold or we otherwise terminate the offering of these securities; provided, however, that we are not incorporating by reference any additional documents or information "furnished" and not "filed" with the SEC. You may obtain copies of any of these filings by contacting us at the following address and phone number or by contacting the SEC or NYSE as described above. Documents incorporated by reference are available from us without charge, excluding all exhibits unless an exhibit has been specifically incorporated by reference into this prospectus, by requesting them in writing, by telephone or via the Internet at:

CubeSmart
Attention: Investor Relations
5 Old Lancaster Road
Malvern, PA 19355
Phone: (610) 535-5000
Internet Website: www.cubesmart.com

The information contained on our website does not constitute a part of this prospectus, and our website address supplied above is intended to be an inactive textual reference only and not an active hyperlink to our website.

This prospectus and any accompanying prospectus supplement, together with other documents and information incorporated by reference into this prospectus and any accompanying prospectus supplement, contain certain forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Such statements are based on assumptions and expectations that may not be realized and are inherently subject to risks, uncertainties and other factors, many of which cannot be predicted with accuracy and some of which might not even be anticipated. Although we believe the expectations reflected in these forward-looking statements are based on reasonable assumptions, future events and actual results, performance, transactions or achievements, financial and otherwise, may differ materially from the results, performance, transactions or achievements expressed or implied by the forward-

looking statements contained in or contemplated by this prospectus or any prospectus supplement. Any forward-looking statements should be considered in light of the risks and uncertainties referred to in Item 1A. "Risk Factors" in CubeSmart's and the Operating Partnership's Annual Report on Form 10-K for the year ended December 31, 2016 and in our periodic reports and other information that we subsequently file with the SEC. The most significant of these risks, uncertainties and other factors that might cause such differences include, but are not limited to:

In light of these uncertainties and risks, prospective investors are cautioned not to place undue reliance on these forward-looking statements. Except with respect to such material changes to our risk factors as may be reflected from time to time in our quarterly filings or as otherwise required by law, we are under no obligation to, and expressly disclaim any obligation to, update or revise any forward-looking statements included or incorporated by reference in this prospectus or any accompanying prospectus supplement, whether as a result of new information, future events or otherwise. Because of the factors referred to above, the future events discussed in or incorporated by reference in this prospectus or any accompanying prospectus supplement may not occur and actual results, performance or achievement could differ materially from that anticipated or implied in the forward-looking statements.

We are a self-administered and self-managed real estate company focused primarily on the ownership, operation, management, acquisition, and development of self-storage properties in the United States.

CubeSmart was formed in July 2004 as a Maryland REIT. CubeSmart owns its assets and conducts its business through the Operating Partnership, and its subsidiaries. CubeSmart controls the Operating Partnership as its sole general partner and, as of March 17, 2017, owned an approximately 98.9% interest in the Operating Partnership. The Operating Partnership was formed in July 2004 as a Delaware limited partnership and has been engaged in virtually all aspects of the self-storage business, including the development, acquisition, management, ownership and operation of self-storage properties.

Our self-storage properties are designed to offer affordable and easily-accessible storage space for our residential and commercial customers. Our customers rent storage cubes for their exclusive use, typically on a month-to-month basis. Additionally, some of our stores offer outside storage areas for vehicles and boats. Our stores are designed to accommodate both residential and commercial customers, with features such as wide aisles and load-bearing capabilities for large truck access. All of our stores have a storage associate available to assist our customers during business hours, and many of our owned stores have a manager who resides in an apartment at the store. Our customers can access their storage cubes during business hours, and some of our stores provide customers with 24-hour access through computer-controlled access systems. Our goal is to provide customers with the highest standard of physical attributes and service in the industry. To that end, many of our owned facilities include climate-controlled cubes.

Our executive offices are located at 5 Old Lancaster Road, Malvern, PA 19355 and our telephone number is (610) 535-5000.

Investing in our securities involves risks. You should carefully consider the risk factors incorporated by reference to our most recent Annual Report on Form 10-K and the other information contained or incorporated by reference in this prospectus, as updated by our subsequent filings under the Exchange Act, and the risk factors and other information contained in the applicable prospectus supplement before acquiring any of such securities. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities. Please also refer to the section above entitled "Forward-Looking Statements."

Unless otherwise indicated in the applicable prospectus supplement, CubeSmart will contribute or otherwise transfer the net proceeds of any sale of securities to the Operating Partnership in exchange for additional partnership interests in the Operating Partnership, the economic terms of which will be substantially identical to those of the securities sold. We will not receive any proceeds from the resale by any selling securityholders of common shares.

Unless otherwise indicated in the applicable prospectus supplement, the Operating Partnership will use those net proceeds and any net proceeds from any sale of its debt securities for general business purposes, including, without limitation, repayment of outstanding debt, acquisitions, developments, capital expenditures, working capital and other general corporate purposes.

RATIO OF EARNINGS TO FIXED CHARGES AND RATIO OF EARNINGS TO COMBINED FIXED
CHARGES AND PREFERENCE DIVIDENDS

The following table sets forth the Operating Partnership's ratios of earnings to fixed charges for the periods indicated.

The following table sets forth CubeSmart's ratios of earnings to combined fixed charges and preference dividends for the periods indicated.

For the purpose of calculating the ratio of earnings to combined fixed charges and preference dividends, earnings consist of income (loss) from continuing operations, plus fixed charges less capitalized interest. Fixed charges consist of interest expense, capitalized interest, amortized premiums, discounts and capitalized expenses relating to debt and an estimate of the interest component of rent expense. Preference dividends includes income allocated to holders of CubeSmart's preferred shares.

(a): In fiscal 2012, earnings were insufficient to cover combined fixed charges and preference dividends. CubeSmart would have had to generate additional earnings of $19.5 million to achieve a fixed charge coverage ratio of 1:1 in fiscal 2012.
(b): On November 2, 2016, CubeSmart redeemed of all of its 3,100,000 outstanding shares of 7.75% Series A Cumulative Redeemable Preferred Shares at a cash redemption price of $25.00 per share plus accumulated and unpaid dividends up to and including the date of redemption. As of December 31, 2016, CubeSmart had no preferred shares outstanding.

The following description of our capital shares, together with the additional information we include in any applicable prospectus supplement, summarizes the material terms and provisions of the capital shares that may be offered under this prospectus. For the complete terms of our capital shares, please refer to our declaration of trust and bylaws that are filed as exhibits to our reports incorporated by reference into the registration statement of which this prospectus is a part. See "Where You Can Find More Information."

CubeSmart's declaration of trust provides that CubeSmart may issue up to 400,000,000 common shares of beneficial interest, par value $0.01 per share. As of March 15, 2017, there were 180,173,982 common shares issued and outstanding.

Both Maryland statutory law governing real estate investment trusts formed under Maryland law, which we refer to as the Maryland REIT Law, and CubeSmart's declaration of trust provide that none of its shareholders will be personally liable, by reason of status as a shareholder, for any of its obligations.

Subject to the provisions of CubeSmart's declaration of trust regarding restrictions on the transfer and ownership of shares of beneficial interest, each outstanding common share entitles the holder to one vote on all matters submitted to a vote of shareholders, including the election of trustees, and, except as provided with respect to any other class or series of shares of beneficial interest that CubeSmart may issue, the holders of such common shares will possess exclusive voting power. There is no cumulative voting in the election of trustees. As a result, the holders of a majority of the outstanding common shares, voting as a single class, can elect all of the trustees then standing for election. CubeSmart's bylaws provide that a plurality of the votes cast at a meeting of shareholders duly called at which a quorum is present is sufficient to elect a trustee and that a majority of the votes cast at a meeting of shareholders duly called at which a quorum is present is sufficient to approve any other matter which may properly come before the meeting, unless a higher vote is required under CubeSmart's bylaws, CubeSmart's declaration of trust or applicable statute.

Under the Maryland REIT law, a Maryland REIT generally cannot amend its declaration of trust or merge with another entity without the affirmative vote of shareholders holding at least two-thirds of the shares entitled to vote on the matter unless a lesser percentage (but not less than a majority of all the votes entitled to be cast on the matter) is set forth in the REIT's declaration of trust. Our declaration of trust provides that amendments to the declaration of trust and our merger with another entity may be approved by the affirmative vote of the holders of not less than a majority of all votes entitled to be cast on the matter. Under the Maryland REIT law and CubeSmart's declaration of trust, its trustees will be permitted to amend the declaration of trust from time to time to maintain our qualification as a REIT under the Internal Revenue Code of 1986, as amended, or the Code, and under the Maryland REIT law, without the affirmative vote or written consent of the shareholders.

All common shares offered by this prospectus will be duly authorized, fully paid and nonassessable. Holders of CubeSmart's common shares are entitled to receive dividends and distributions when authorized by our board of trustees, and declared by CubeSmart out of assets legally available for the payment of dividends or distributions. They also are entitled to share ratably in CubeSmart's assets legally available for distribution to its shareholders in the event of CubeSmart's liquidation, dissolution or winding up, after payment of or adequate provision for all of its known debts and liabilities. These rights are subject to the preferential rights of the holders of any class or series of CubeSmart's preferred shares and to the provisions of CubeSmart's declaration of trust regarding restrictions on transfer of its shares.

Holders of CubeSmart's common shares have no preference, conversion, exchange, sinking fund, redemption or appraisal rights and have no preemptive rights to subscribe for any of our securities.

Subject to the restrictions on transfer of shares contained in CubeSmart's declaration of trust and to the power of the board of trustees to create common shares with differing voting rights, all common shares have equal dividend, liquidation and other rights.

CubeSmart's declaration of trust provides that it may issue up to 40,000,000 preferred shares of beneficial interest, par value $0.01 per share. As of March 17, 2017, there were no preferred shares issued and outstanding.

CubeSmart's board of trustees is authorized to issue the preferred shares in one or more series and to fix and designate the rights, preferences, privileges and restrictions of the preferred shares, including:

The rights, preferences, privileges and restrictions of the preferred shares of each series will be fixed by articles supplementary relating to each series. We will describe the specific terms of a particular series of preferred shares in the prospectus supplement relating to that series, including:

CubeSmart's board of trustees could authorize, without shareholder approval, the issuance of preferred shares with terms and conditions that could have the effect of discouraging a takeover or other transaction in which holders of some or a majority of CubeSmart's shares might receive a premium for their shares over the then-prevailing market price of its shares. We currently do not expect that the board of trustees would require shareholder approval prior to such a preferred issuance. In addition, any preferred shares that CubeSmart issues would rank senior to its common shares with respect to the payment of distributions, in which case CubeSmart could not pay any distributions on its common shares until full distributions have been paid with respect to such preferred shares.

Power to Reclassify Shares and Issue Additional Common Shares or Preferred Shares

CubeSmart's declaration of trust authorizes its board of trustees to classify any authorized but unissued common and preferred shares and to reclassify any previously classified but unissued common shares and preferred shares of any series from time to time in one or more series, as authorized by the board of trustees. Prior to the issuance of shares of each class or series, the board of trustees is required by the Maryland REIT law and CubeSmart's declaration of trust to establish for each such class or series, subject to the provisions of CubeSmart's declaration of trust regarding the restrictions on transfer of shares of beneficial interest, the terms, preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends or other distributions, qualifications and terms or conditions of redemption for each such class or series. As a result, CubeSmart's board of trustees could authorize the issuance of preferred shares that have priority over the common shares with respect to dividends, distributions and rights upon liquidation and with other terms and conditions that could have the effect of delaying, deterring or preventing a transaction or a change in control that might involve a premium price for holders of common shares or otherwise might be in their best interest.

To permit us increased flexibility in structuring possible future financings and acquisitions and in meeting other needs that might arise, CubeSmart's declaration of trust allows us to issue additional common shares or preferred shares and to classify or reclassify unissued common shares or preferred shares and thereafter to issue the classified or reclassified shares without shareholder approval, unless shareholder approval is required by applicable law or the rules of any stock exchange or automated quotation system on which CubeSmart's securities may be listed or traded. Although we have no present intention of doing so, we could issue a class or series of shares that could delay, deter or prevent a transaction or a change in control that might involve a premium price for holders of common shares or might otherwise be in their best interests.

In order to qualify as a REIT under the Code, CubeSmart's shares must be beneficially owned by 100 or more persons during at least 335 days of a taxable year of 12 months or during a proportionate part of a shorter taxable year. Also, no more than 50% of the value of CubeSmart's outstanding shares (after taking into account options to acquire shares) may be owned, directly, indirectly or through attribution, by five or fewer individuals (as defined in the Code to include certain entities).

Because CubeSmart's board of trustees believes that it is in CubeSmart's shareholders' best interests to continue to qualify as a REIT and for anti-takeover and other strategic reasons, its declaration of trust, subject to certain exceptions, contains restrictions on the number of CubeSmart's shares of beneficial interest that a person may own. CubeSmart's declaration of trust provides that:

CubeSmart's board of trustees may exempt a person from the 9.8% ownership limit, for a shareholder that is not an individual if such shareholder provides information and makes representations to the board of trustees that are satisfactory to the board of trustees, in its reasonable discretion, to establish that such person's ownership in excess of the 9.8% limit would not jeopardize CubeSmart's qualification as a REIT.

Any person who acquires or attempts or intends to acquire beneficial or constructive ownership of CubeSmart's shares that will or may violate any of the foregoing restrictions on transferability and ownership will be required to give notice immediately to us and provide us with such other information as we may request in order to determine the effect of such transfer on CubeSmart's status as a REIT. If any transfer of shares or any other event would otherwise result in any person violating the ownership limits described above, then CubeSmart's declaration of trust provides that (a) the transfer will be void and of no force or effect with respect to the prohibited transferee with respect to that number of shares that exceeds the ownership limits or that such number of shares will be automatically transferred to a charitable trust for the benefit of a charitable beneficiary and (b) the prohibited transferee would not acquire any right or interest in the shares. The foregoing restrictions on transferability and ownership will not apply if CubeSmart's board of trustees determines that it is no longer in CubeSmart's best interests to attempt to qualify, or to continue to qualify, as a REIT.

All certificates evidencing CubeSmart's shares bear a legend referring to the restrictions described above.

Every owner of more than 5% (or such lower percentage as required by the Code or the regulations promulgated thereunder) of all classes or series of CubeSmart's shares, including common shares, is required to give written notice to us within 30 days after the end of each taxable year stating the name and address of such owner, the number of shares of each class and series of shares that the owner beneficially owns and a description of the manner in which such shares are held. Each such owner shall provide to us such additional information as we may request in order to determine the effect, if any, of such beneficial ownership on CubeSmart's status as a REIT and to ensure compliance with the ownership limitations. In addition, each shareholder shall upon demand be required to provide to us such information as we may request, in good faith, in order to determine CubeSmart's status as a REIT and to comply with the requirements of any taxing authority or governmental authority or to determine such compliance.

These ownership limitations could delay, deter or prevent a transaction or a change in control that might involve a premium price for the common shares or might otherwise be in the best interest of CubeSmart's shareholders.

The transfer agent and registrar for our common shares is American Stock Transfer & Trust Co., LLC. The transfer agent and registrar for our preferred shares will be set forth in the applicable prospectus supplement.

Certain Provisions of Maryland Law and CubeSmart's Declaration of Trust and Bylaws

The following description of certain provisions of Maryland law and of CubeSmart's declaration of trust and bylaws is only a summary. For a complete description, we refer you to the applicable Maryland law and CubeSmart declaration of trust and bylaws.

CubeSmart's declaration of trust and bylaws provide that the number of CubeSmart's trustees shall not be less than one and not more than 13, and will be established by a vote of a majority of the members of its board of trustees. Our bylaws provide that any vacancy, including a vacancy created by an increase in the number of trustees, may be filled only by a majority of the remaining trustees, even if the remaining trustees do not constitute a quorum. Pursuant to CubeSmart's declaration of trust, each of its trustees is elected by its shareholders to serve until the next annual meeting and until their successors are duly elected and qualify. Under Maryland law, CubeSmart's board of trustees may elect to create staggered terms for its members.

CubeSmart's bylaws provide that at least a majority of our trustees will be "independent," with independence being defined in the manner established by our board of trustees and in a manner consistent with listing standards established by the NYSE.

CubeSmart's declaration of trust provides that a trustee may be removed only with cause and only upon the affirmative vote of at least two-thirds of the votes entitled to be cast in the election of trustees. Absent removal of all of CubeSmart's trustees, this provision, when coupled with the provision in CubeSmart's bylaws authorizing CubeSmart's board of trustees to fill vacant trusteeships, may preclude shareholders from removing incumbent trustees and filling the vacancies created by such removal with their own nominees.

CubeSmart's board of trustees has approved a resolution that exempts CubeSmart from the provisions of the Maryland business combination statute described below, but its board of trustees may opt to make these provisions applicable to CubeSmart in the future. Maryland law prohibits "business combinations" between CubeSmart and an interested shareholder (defined below) or an affiliate of an interested shareholder for five years after the most recent date on which the interested shareholder becomes an interested shareholder. These business combinations include a merger, consolidation, share exchange, or, in circumstances specified in the statute, an asset transfer or issuance or reclassification of equity securities. Maryland law defines an interested shareholder as:

A person is not an interested shareholder if CubeSmart's board of trustees approves in advance the transaction by which the person otherwise would have become an interested shareholder. However, in approving a transaction, CubeSmart's board of trustees may provide that its approval is subject to compliance, at or after the time of approval, with any terms and conditions determined by CubeSmart's board of trustees.

After the five-year prohibition, any business combination between CubeSmart and an interested shareholder generally must be recommended by CubeSmart's board of trustees and approved by the affirmative vote of at least:

These super-majority vote requirements do not apply if CubeSmart's common shareholders receive a minimum price, as described under Maryland law, for their shares in the form of cash or other consideration in the same form as previously paid by the interested shareholder for its shares.

The statute permits various exemptions from its provisions, including business combinations that are approved by CubeSmart's board of trustees before the time that the interested shareholder becomes an interested shareholder.

CubeSmart's bylaws contain a provision exempting any and all acquisitions of CubeSmart's shares from the provisions of the Maryland Control Share Acquisition Act. However, CubeSmart's board of trustees may opt to make these provisions applicable to an acquisition of CubeSmart's shares at any time by amending or repealing this provision in the future, and may do so on a retroactive basis. Maryland law provides that "control shares" of a Maryland REIT acquired in a "control share acquisition" have no voting rights unless approved by a vote of two-thirds of the votes entitled to be cast on the matter. Shares beneficially owned by the acquiring person in a control share acquisition or by CubeSmart's officers or employees who are CubeSmart's trustees are excluded from the shares entitled to vote in accordance with the immediately preceding sentence. "Control shares" are shares that, if aggregated with all other shares previously acquired by the acquiring person, or in respect of which the acquiring person is able to exercise or direct the exercise of voting power (except solely by virtue of a revocable proxy), would entitle the acquiring person to exercise or direct the exercise of the voting power in electing trustees within one of the following ranges of voting power:

Control shares do not include shares the acquiring person is then entitled to vote as a result of having previously obtained shareholder approval. A "control share acquisition" means the acquisition of control shares, subject to certain exceptions.

A person who has made or proposes to make a control share acquisition may compel our board of trustees to call a special meeting of shareholders to be held within 50 days of demand to consider the voting rights of the shares. The right to compel the calling of a special meeting is subject to the satisfaction of certain conditions, including an undertaking to pay the expenses of the special meeting. If no request for a special meeting is made, we may present the question at any shareholders' meeting.

If voting rights are not approved at the shareholders' meeting or if the acquiring person does not deliver the statement required by Maryland law, then, subject to certain conditions and limitations, we may redeem any or all of the control shares, except those for which voting rights have previously been approved, for fair value. Fair value is determined without regard to the absence of voting rights for the

control shares and as of the date of the last control share acquisition or of any meeting of shareholders at which the voting rights of the shares were considered and not approved. If voting rights for control shares are approved at a shareholders' meeting, the acquiror may then vote a majority of the shares entitled to vote, and all other shareholders may exercise appraisal rights. The fair value of the shares for purposes of these appraisal rights may not be less than the highest price per share paid by the acquiror in the control share acquisition. The control share acquisition statute does not apply to shares acquired in a merger, consolidation or share exchange if we are a party to the transaction, nor does it apply to acquisitions approved by or exempted by our declaration of trust or bylaws.

Possible Anti-Takeover Effect of Certain Provisions of Maryland Law and CubeSmart's Declaration of Trust and Bylaws

The business combination provisions of Maryland law (if CubeSmart's board of trustees opts to make them applicable to CubeSmart), the control share acquisition provisions of Maryland law (if the applicable provision in CubeSmart's bylaws is rescinded), the limitations on removal of trustees, the restrictions on the acquisition of CubeSmart's shares of beneficial interest, the power to issue additional common shares or preferred shares and the advance notice provisions for shareholder trustee nominations and other shareholder proposals of our bylaws could have the effect of delaying, deterring or preventing a transaction or a change in control that might involve a premium price for holders of the common shares or might otherwise be in their best interest. The "unsolicited takeovers" provisions of Maryland law permit our board of trustees, without shareholder approval and regardless of what is provided in our declaration of trust or bylaws, to implement takeover defenses that we may not yet have.

CubeSmart may elect to have shares of preferred shares represented by depositary shares. The shares of any series of the preferred shares underlying the depositary shares will be deposited under a separate deposit agreement between CubeSmart and a bank or trust company that we select. The prospectus supplement relating to a series of depositary shares will set forth the name and address of this preferred shares depositary. Subject to the terms of the deposit agreement, each owner of a depositary share will be entitled, proportionately, to all the rights, preferences and privileges of the preferred shares represented by such depositary share, including dividend, voting, redemption, conversion, exchange and liquidation rights. As of the date of this prospectus, there are no depositary shares outstanding.

The depositary shares will be evidenced by depositary receipts issued pursuant to the deposit agreement, each of which will represent the applicable interest in a number of shares of a particular series of the preferred shares described in the applicable prospectus supplement.

A holder of depositary shares will be entitled to receive the shares of preferred shares, but only in whole shares of preferred shares, underlying those depositary shares. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the whole number of shares of preferred shares to be withdrawn, the depositary will deliver to that holder at the same time a new depositary receipt for the excess number of depositary shares.

The preferred shares depositary will distribute all cash dividends or other cash distributions in respect of the series of preferred shares represented by the depositary shares to the record holders of depositary receipts in proportion, to the extent possible, to the number of depositary shares owned by those holders. The depositary, however, will distribute only the amount that can be distributed without

attributing to any depositary share a fraction of one cent, and any undistributed balance will be added to and treated as part of the next sum received by the depositary for distribution to record holders of depositary receipts then outstanding.

If there is a distribution other than in cash in respect of the preferred shares, the preferred shares depositary will distribute property received by it to the record holders of depositary receipts in proportion, insofar as possible, to the number of depositary shares owned by those holders, unless the preferred shares depositary determines that it is not feasible to make such a distribution. In that case, the preferred shares depositary may, with our approval, adopt any method that it deems equitable and practicable to effect the distribution, including a public or private sale of the property and distribution of the net proceeds from the sale to the holders.

The amount distributed in any of the above cases will be reduced by any amount we or the preferred shares depositary are required to withhold on account of taxes.

If any series of preferred shares underlying the depositary shares is subject to provisions relating to its conversion or exchange as set forth in an applicable prospectus supplement, each record holder of depositary receipts will have the right or obligation to convert or exchange the depositary shares evidenced by the depositary receipts pursuant to those provisions.

If any series of preferred shares underlying the depositary shares is subject to redemption, the depositary shares will be redeemed from the proceeds received by the preferred shares depositary resulting from the redemption, in whole or in part, of the preferred shares held by the preferred shares depositary. Whenever CubeSmart redeems a share of preferred shares held by the preferred shares depositary, the preferred shares depositary will redeem as of the same redemption date a proportionate number of depositary shares representing the shares of preferred shares that were redeemed. The redemption price per depositary share will be equal to the aggregate redemption price payable with respect to the number of shares of preferred shares underlying the depositary shares. If fewer than all the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by lot or proportionately as CubeSmart may determine.

After the date fixed for redemption, the depositary shares called for redemption will no longer be deemed to be outstanding and all rights of the holders of the depositary shares will cease, except the right to receive the redemption price. Any funds that we deposit with the preferred shares depositary relating to depositary shares which are not redeemed by the holders of the depositary shares will be returned to us after a period of two years from the date the funds are deposited by CubeSmart.

Upon receipt of notice of any meeting at which the holders of any shares of preferred shares underlying the depositary shares are entitled to vote, the preferred shares depositary will mail the information contained in the notice to the record holders of the depositary receipts. Each record holder of the depositary receipts on the record date, which will be the same date as the record date for the preferred shares, may then instruct the preferred shares depositary as to the exercise of the voting rights pertaining to the number of shares of preferred shares underlying that holder's depositary shares. The preferred shares depositary will try to vote the number of shares of preferred shares underlying the depositary shares in accordance with the instructions, and we will agree to take all reasonable action which the preferred shares depositary deems necessary to enable the preferred shares depositary to do so. The preferred shares depositary will abstain from voting the preferred shares to the extent that it

does not receive specific written instructions from holders of depositary receipts representing the preferred shares.

Upon surrender of depositary receipts at the principal office of the preferred shares depositary, upon payment of any unpaid amount due the preferred shares depositary, and subject to the terms of the deposit agreement, the owner of the depositary shares evidenced by the depositary receipts is entitled to delivery of the number of whole shares of preferred shares and all money and other property, if any, represented by the depositary shares. Partial shares of preferred shares will not be issued. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the number of depositary shares representing the number of whole shares of preferred shares to be withdrawn, the preferred shares depositary will deliver to the holder at the same time a new depositary receipt evidencing the excess number of depositary shares. Holders of preferred shares that are withdrawn will not be entitled to deposit the shares that have been withdrawn under the deposit agreement or to receive depositary receipts.

CubeSmart and the preferred shares depositary may at any time agree to amend the form of depositary receipt and any provision of the deposit agreement. However, any amendment that materially and adversely alters the rights of holders of depositary shares will not be effective unless the amendment has been approved by the holders of at least a majority of the depositary shares then outstanding. The deposit agreement may be terminated by CubeSmart or by the preferred shares depositary only if all outstanding shares have been redeemed or if a final distribution in respect of the underlying preferred shares has been made to the holders of the depositary shares in connection with our liquidation, dissolution or winding up.

CubeSmart will pay all charges of the preferred shares depositary including charges in connection with the initial deposit of the preferred shares, the initial issuance of the depositary receipts, the distribution of information to the holders of depositary receipts with respect to matters on which preference shares is entitled to vote, withdrawals of the preferred shares by the holders of depositary

receipts or redemption or conversion of the preferred shares, except for taxes (including transfer taxes, if any) and other governmental charges and any other charges expressly provided in the deposit agreement to be at the expense of holders of depositary receipts or persons depositing preferred shares.

Neither CubeSmart nor the preferred shares depositary will be liable if either of us is prevented or delayed by law or any circumstance beyond our control in performing any obligations under the deposit agreement. The obligations of the preferred shares depositary under the deposit agreement are limited to performing its duties under the agreement without negligence or bad faith. Our obligations under the deposit agreement are limited to performing our duties in good faith. Neither CubeSmart nor the preferred shares depositary is obligated to prosecute or defend any legal proceeding in respect of any depositary shares or preferred shares unless satisfactory indemnity is furnished. CubeSmart and the preferred shares depositary may rely on advice of or information from counsel, accountants or other persons that they believe to be competent and on documents that they believe to be genuine.

The preferred shares depositary may resign at any time or be removed by CubeSmart, effective upon the acceptance by its successor of its appointment. If CubeSmart has not appointed a successor preferred shares depositary and the successor depositary has not accepted its appointment within 60 days after the preferred shares depositary delivered a resignation notice to CubeSmart, the preferred shares depositary may terminate the deposit agreement. See "Amendment and Termination of the Deposit Agreement" above.

CubeSmart may issue subscription rights to purchase common shares, preferred shares, or depositary shares. CubeSmart may issue subscription rights independently or together with any other offered security, which may or may not be transferable by the shareholder. In connection with any offering of subscription rights, CubeSmart may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after such offering.

The prospectus supplement relating to any subscription rights CubeSmart may offer will contain the specific terms of the subscription rights. These terms may include the following:

The description in the applicable prospectus supplement of any subscription rights CubeSmart offers will not necessarily be complete and will be qualified in its entirety by reference to the applicable subscription rights certificate or subscription rights agreement, which will be filed with the SEC if CubeSmart offers subscription rights. For more information on how you can obtain copies of any subscription rights certificate or subscription rights agreement if CubeSmart offers subscription rights, see "Where You Can Find More Information." CubeSmart urges you to read the applicable subscription rights certificate, the applicable subscription rights agreement and any applicable prospectus supplement in their entirety.

CubeSmart may issue warrants for the purchase of common shares, preferred shares or depositary shares. CubeSmart may issue warrants independently or together with any offered securities. The warrants may be attached to or separate from those offered securities. CubeSmart will issue the warrants under one or more warrant agreements to be entered into between CubeSmart and a warrant agent to be named in the applicable prospectus supplement. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants.

The prospectus supplement relating to any warrants that CubeSmart may offer will contain the specific terms of the warrants. These terms may include the following:

Each warrant will entitle the holder of the warrant to purchase for cash the amount of CubeSmart's common shares, preferred shares and/or depositary shares, as the case may be, at the

exercise price stated or determinable in the applicable prospectus supplement for the warrants. Warrants may be exercised at any time up to the close of business on the expiration date shown in the applicable prospectus supplement, unless otherwise specified in such prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void. Warrants may be exercised as described in the applicable prospectus supplement. When the warrant holder makes the payment and properly completes and signs the warrant certificate at the corporate trust office of the warrant agent or any other office indicated in the prospectus supplement, CubeSmart will, as soon as possible, forward the common shares, preferred shares and/or depositary shares that the warrant holder has purchased, as the case may be. If the warrant holder exercises the warrant for less than all of the warrants represented by the warrant certificate, CubeSmart will issue a new warrant certificate for the remaining warrants.

The description in the applicable prospectus supplement of any warrants CubeSmart offers will not necessarily be complete and will be qualified in its entirety by reference to the applicable warrant agreement and warrant certificate, which will be filed with the SEC if CubeSmart offers warrants. For more information on how you can obtain copies of any warrant certificate or warrant agreement if we offer warrants, see "Where You Can Find More Information." We urge you to read the applicable warrant certificate, the applicable warrant agreement and any applicable prospectus supplement in their entirety.

The following summary sets forth the general terms and provisions of the indenture under which the debt securities will be issued by the Operating Partnership. The debt securities will be issued by the Operating Partnership under an indenture, as amended or supplemented from time to time, among the Operating Partnership, CubeSmart, as guarantor, and U.S. Bank National Association, as trustee, or such other trustee selected by the Operating Partnership.

The debt securities may be issued from time to time in one or more series. The particular terms and provisions of the debt securities with respect to a specific offering of debt securities will be set forth in the applicable prospectus supplement. This summary of general terms and provisions of the indenture and the debt securities does not purport to be complete and is subject to, and is qualified in its entirety by reference to, all provisions of the indenture and those debt securities.

The indenture is filed as an exhibit to the registration statement of which this prospectus is a part and will be available for inspection at the corporate trust office of the trustee or as described under "Where You Can Find More Information." The indenture will be qualified under, subject to, and governed by, the Trust Indenture Act of 1939, as amended, or the Trust Indenture Act.

All section references appearing herein are to sections of the indenture, and capitalized terms used but not defined herein will have the respective meanings set forth in the indenture.

The debt securities will be direct, unsecured obligations of the Operating Partnership. Except for any series of debt securities which is expressly subordinated to other indebtedness of the Operating Partnership, the debt securities will rank equally with all other unsecured and unsubordinated indebtedness of the Operating Partnership. Under the indenture, the debt securities may be issued without limit as to aggregate principal amount, in one or more series, as established from time to time pursuant to authority granted by a resolution of the board of trustees of CubeSmart as sole general partner of the Operating Partnership or as established in one or more supplemental indentures to the indenture. All of the debt securities of any one series need not be issued at the same time and, unless otherwise provided, a series may be reopened, without the consent of the holders of the debt securities of that series, for issuances of additional debt securities of that series. All debt securities of a particular

series shall be substantially identical except as to denomination, date of issuance, issue price and the date from which interest, if any, shall accrue.

All of the debt securities will be fully and unconditionally guaranteed as to payment of principal and premium, if any, and interest by CubeSmart. The indenture allows certain of our subsidiaries from time to time to become guarantors of specific series of the debt securities.

The indenture provides that there may be more than one trustee for any one or more series of debt securities. Any trustee under the indenture may resign or be removed with respect to one or more series of debt securities, and a successor trustee may be appointed to act with respect to that series. Except as otherwise indicated in this prospectus or the applicable prospectus supplement, any action to be taken by the trustee may be taken by each such trustee with respect to, and only with respect to, the one or more series of debt securities for which it is trustee under the indenture.

The applicable prospectus supplement relating to the series of debt securities being offered will describe the specific terms and provisions of those debt securities, including the following:

The debt securities may provide for less than the entire principal amount of those debt securities to be payable upon declaration of acceleration of the maturity thereof, or original issue discount securities. The applicable prospectus supplement will describe special U.S. federal income tax, accounting and other considerations applicable to the original issue discount securities.

The indenture does not contain any provisions that would limit the ability of the Operating Partnership to incur indebtedness or that would afford holders of debt securities protection in the event of a highly leveraged or similar transaction involving the Operating Partnership. However, restrictions on ownership and transfers of CubeSmart's common shares and preferred shares, designed to preserve CubeSmart's status as a REIT, may prevent or hinder a change of control. Reference is made to the applicable prospectus supplement for information with respect to any deletions from, modifications of or additions to the events of default or covenants of the Operating Partnership that are described below, including any addition of a covenant or other provision providing event risk or similar protection.

CubeSmart will, under the indenture, fully and unconditionally guarantee the due and punctual payment of principal of and premium, if any, and interest on all debt securities issued by the Operating Partnership, and the due and punctual payment of any sinking fund payments on those debt securities, when and as the same will become due and payable, whether at a maturity date, by declaration of acceleration, call for redemption or otherwise.

From time to time, subsidiaries of the Operating Partnership may join as guarantors under the indenture. Such subsidiaries' guarantees will be limited to the series of debt securities for which they execute notations of guarantee in accordance with the terms of the indenture, and may be released in connection with:

The obligations of each guarantor, other than CubeSmart, under its guarantee will be limited as necessary to prevent that guarantee from constituting a fraudulent conveyance or fraudulent transfer under applicable law.

Unless otherwise specified in the applicable prospectus supplement, the debt securities of any series shall be issuable only in registered form without coupons and, other than securities in global form (which may be of any denomination), will be issuable in denominations of $2,000 and integral multiples of $1,000 in excess thereof.

Unless otherwise specified in the applicable prospectus supplement, the principal of and premium, if any, and interest on any series of debt securities will be payable at the corporate trust office of the trustee. However, at the option of the Operating Partnership, payment of interest may be made by check mailed to the address of the person entitled thereto as it appears in the security register or by wire transfer of funds to that person at a bank account maintained within the United States.

All amounts paid by the Operating Partnership to a paying agent or a trustee for the payment of the principal of or premium, if any, or interest on any debt security which remains unclaimed at the end of two years after the principal, premium or interest has become due and payable will be repaid to the Operating Partnership, and the holder of the debt security thereafter may look only to the Operating Partnership for payment of these amounts.

Any interest not punctually paid or duly provided for on any interest payment date with respect to a debt security will forthwith cease to be payable to the holder on the applicable regular record date and may either be paid to the person in whose name that debt security is registered at the close of business on a special record date for the payment of that defaulted interest to be fixed by the trustee or may be paid at any time in any other lawful manner, all in accordance with the indenture. Notice of any special record date will be given to the holder of that debt security not less than 10 days prior to the special record date.

Subject to certain limitations imposed upon debt securities issued in book-entry form, the debt securities of any series will be exchangeable for other debt securities of the same series, of a like aggregate principal amount and tenor, of different authorized denominations upon surrender of such debt securities at the corporate trust office of the trustee. In addition, subject to certain limitations imposed upon debt securities issued in book-entry form, the debt securities of any series may be surrendered for registration of transfer at the corporate trust office of the trustee.

Every debt security surrendered for registration of transfer or exchange will be duly endorsed or accompanied by a written instrument of transfer. No service charge will be made for any registration of transfer or exchange of any debt securities, but the Operating Partnership may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

If the applicable prospectus supplement refers to any transfer agent (in addition to the trustee) initially designated by the Operating Partnership and the guarantors with respect to any series of debt securities, the Operating Partnership may at any time rescind the designation of that transfer agent or approve a change in the location through which that transfer agent acts, except that the Operating Partnership and the guarantors will be required to maintain a transfer agent in each place of payment for that series. The Operating Partnership and the guarantors may at any time designate additional transfer agents with respect to any series of debt securities.

Unless otherwise provided in the applicable prospectus supplement, the Operating Partnership may consolidate with, or sell, lease or convey all or substantially all of its assets to, or merge with or into, any other entity, provided that the following conditions are satisfied or fulfilled:

Unless otherwise provided in the applicable prospectus supplement, CubeSmart may consolidate with, or sell, lease or convey all or substantially all its assets to, or merge with or into, any other entity, provided that substantially the same conditions as above are satisfied or fulfilled.

We will set forth in the applicable prospectus supplement any financial covenants applicable to any issue of debt securities.

Unless otherwise provided in the applicable prospectus supplement, so long as any debt securities are outstanding, CubeSmart and the Operating Partnership will furnish to the trustee such information, documents and other reports as may be required by the Trust Indenture Act, including filing with the trustee within 15 days information, documents or reports required to be filed by the Issuer with the SEC.

The Operating Partnership and the guarantors may choose not to comply with any term, provision or condition of certain covenants if at any time the holders of at least a majority in principal amount of all the outstanding debt securities, by act of those holders, either waive compliance in that instance or generally waive compliance with that covenant. Except to the extent so expressly waived, and until any waiver becomes effective, the Operating Partnership's and the guarantors' obligations and the duties of the trustee in respect of any such term, provision or condition will remain in full force and effect.

Unless otherwise provided in the applicable prospectus supplement, except as permitted under "Merger, Consolidation or Sale," each of the Operating Partnership and the guarantors will do or cause to be done all things necessary to preserve and keep in full force and effect its existence, rights (declaration and statutory) and franchises; provided, however, that neither the Operating Partnership nor any guarantor will be required to preserve any right or franchise if the board of directors of the Operating Partnership, or the board of trustees or analogous body of any subsidiary guarantor, determines that the preservation thereof is no longer necessary or desirable in the conduct of its business and that the loss of that right or franchise is not disadvantageous in any material respect to the holders of the debt securities.

Unless otherwise provided in the applicable prospectus supplement, each of the Operating Partnership and the guarantors will cause all of its material properties used or useful in the conduct of its business or the business of any of its Subsidiaries to be maintained and kept in good condition, repair and working order, all as in the judgment of the Operating Partnership or the applicable guarantor may be necessary so that the business carried on in connection with those properties may be properly and advantageously conducted at all times; provided, however, that, subject to the covenant described under "Merger, Consolidation and Sale" above, neither the Operating Partnership nor any guarantor nor any of their respective Subsidiaries will be prevented from selling or otherwise disposing of their properties at any time.

Unless otherwise provided in the applicable prospectus supplement, each of the Operating Partnership and the guarantors will pay or discharge or cause to be paid or discharged, before becoming delinquent:

provided, however, that neither the Operating Partnership nor any guarantor will be required to pay or discharge or cause to be paid or discharged any tax, assessment, charge or claim whose amount or applicability is being contested in good faith.

Unless otherwise provided in the applicable prospectus supplement, each of the Operating Partnership and the guarantors will pay to any holder of debt securities that is a United States Alien such additional amounts as may be required such that every net payment on the debt securities held by such holder, after deduction or withholding on account of any present or future U.S. tax (other than taxes unrelated to the holder's ownership of the debt securities and certain other taxes), is not less than the amount provided in such debt securities as then due and payable.

The applicable prospectus supplement relating to the series of debt securities being offered will describe any additional covenants specific to that series.

Unless otherwise provided in the applicable prospectus supplement, the indenture provides that the following events will be "events of default" with respect to any series of debt securities issued under the indenture:

Unless otherwise provided in the applicable prospectus supplement, if an event of default (other than as described in clause (6) above) with respect to debt securities of any series at the time outstanding occurs and is continuing, then in each case the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may declare the principal (or, if the debt securities of that series are original issue discount securities or indexed securities, that portion of the principal amount as may be specified in the terms thereof) of and premium, if any, and accrued and unpaid interest on all of the debt securities of that series to be due and payable immediately by written notice thereof to the Operating Partnership and CubeSmart (and to the trustee if given by the holders). If an event of default described in clause (6) above occurs and is continuing, the principal (or such portion thereof) of and premium, if any, and accrued and unpaid interest on all of the debt securities of that series will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holders. However, at any time after any acceleration with respect to debt securities of that series, but before a judgment or decree for payment of the amounts due has been obtained by the trustee, the holders of not less than a majority in principal amount of outstanding debt securities of that series may rescind and annul that acceleration and its consequences if (1) the Operating Partnership or any guarantor has paid or deposited with the trustee all required payments of the principal of and premium, if any, and interest on the debt securities of that series (without giving effect to the acceleration) plus certain fees, expenses, disbursements and, premium, if any, advances of the trustee and (2) all events of default, other than the nonpayment of accelerated principal, premium, if any, or interest with respect to debt securities of that series, have been cured or waived as provided in the indenture. The indenture also provides that the holders of not less than a majority in principal amount of the outstanding debt securities of any series may waive any past default with respect to that series and its consequences, except a default (A) in the payment of the principal of or premium, if any, or interest on any debt security of that series or (B) in respect of a covenant or provision contained in the indenture that cannot be modified or amended without the consent of the holder of each outstanding debt security affected thereby.

The trustee will be required to give notice to the holders of debt securities within 90 days of a default under the indenture unless such default has been cured or waived; provided, however, that the trustee may withhold notice to the holders of any series of debt securities of any default with respect to that series (except a default in the payment of the principal of or premium, if any, or interest on any debt securities of that series or in the payment of any sinking fund installment in respect of any debt securities of that series) if the responsible officers of the trustee consider withholding of notice to be in the interest of the holders.

The indenture provides that no holders of debt securities of any series may institute any judicial or other proceedings with respect to the indenture or for any remedy thereunder, except in the case of failure of the trustee, for 60 days, to act after it has received a written request to institute proceedings in respect of an event of default from the holders of not less than 25% in principal amount of the outstanding debt securities of that series, as well as an offer of reasonable security or indemnity. This provision will not prevent, however, any holder of debt securities from instituting suit for the enforcement of payment of the principal of and premium, if any, and interest on the debt securities at the respective due date or dates for payment.

Subject to provisions in the indenture relating to its duties in case of default, the trustee is under no obligation to exercise any of its rights or powers under the indenture at the request or direction of any holders of debt securities of any series then outstanding under the indenture, unless the holders offer to the trustee reasonable security or indemnity. The holders of not less than a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or of exercising any trust or power conferred upon the trustee for that series. However, the trustee may refuse to follow any direction which is in conflict with any law or the indenture, which may involve the

trustee in personal liability or which may be unduly prejudicial to the holders of debt securities of that series not joining in the proceeding.

Within 120 days after the end of each fiscal year, the Operating Partnership and CubeSmart must deliver to the trustee a certificate, signed by one of several specified officers of the general partner of the Operating Partnership and of CubeSmart, stating whether or not such officers have knowledge of any default under the indenture and, if so, specifying each such default and the nature and status thereof.

Modifications and amendments of provisions of the indenture applicable to any series may be made only with consent of the holders of more than 50% in principal amount of all outstanding debt securities which are affected by the modification or amendment; provided, however, that no such modification or amendment may, without the consent of the holder of each debt security affected thereby:

Modifications and amendments of the indenture may be made by the Operating Partnership, the guarantors and the trustee without the consent of any holder of debt securities for any of the following purposes:

The indenture provides that, in determining whether the holders of the requisite principal amount of outstanding debt securities of a series have given any request, demand, authorization, direction, notice, consent or waiver thereunder or whether a quorum is present at a meeting of holders of debt securities:

The indenture contains provisions for convening meetings of the holders of debt securities of a series. A meeting may be called at any time by the trustee, and also, upon request, by the Operating Partnership or the holders of at least 25% in principal amount of the outstanding debt securities of that series, in each case upon notice given as provided in the indenture. Except for any consent that must be given by the holder of each debt security affected by certain modifications and amendments of the indenture, any resolution presented at a meeting or adjourned meeting duly reconvened at which a quorum is present may be adopted by the affirmative vote of the holders of a majority in principal amount of the outstanding debt securities of that series; provided, however, that, except as referred to above, any resolution with respect to any request, demand, authorization, direction, notice, consent, waiver or other action that may be made, given or taken by the holders of a specified percentage, which is less than a majority, in principal amount of the outstanding debt securities of a series may be adopted at a meeting or adjourned meeting duly reconvened at which a quorum is present by the affirmative vote of the holders of the debt securities of that series. Any resolution passed or decision taken at any meeting of holders of debt securities of any series duly held in accordance with the indenture will be binding on all holders of debt securities of that series. The quorum at any meeting called to adopt a resolution, and at any reconvened meeting, will be persons holding or representing a majority in principal amount of the outstanding debt securities of a series; provided, however, that if any action is to be taken at such meeting with respect to a consent or waiver which may be given by the holders of not less than a specified percentage in principal amount of the outstanding debt securities of a series, the persons holding or representing such specified percentage in principal amount of the outstanding debt securities of such series will constitute a quorum.

Notwithstanding the foregoing provisions, if any action is to be taken at a meeting of holders of debt securities of any series with respect to any request, demand, authorization, direction, notice, consent, waiver or other action that the indenture expressly provides may be made, given or taken by the holders of a specified percentage in principal amount of all outstanding debt securities affected thereby, or of the holders of that series and one or more additional series:

Unless otherwise provided in the applicable prospectus supplement, the Operating Partnership and the guarantors may discharge certain obligations to holders of any series of debt securities that have not already been delivered to the trustee for cancellation and that either have become due and payable or will become due and payable within one year (or are scheduled for redemption within one year) by irrevocably depositing with the trustee, in trust, funds in such currency or currencies, currency unit or units or composite currency or currencies in which such debt securities are payable in an amount sufficient to pay the entire indebtedness on such debt securities in respect of principal and premium, if any, and interest to the date of such deposit (if such debt securities have become due and payable) or to the stated maturity or redemption date, as the case may be.

In addition, the indenture provides that, unless otherwise provided in the applicable prospectus supplement, the Operating Partnership may elect either:

in either case upon the irrevocable deposit by the Operating Partnership or the guarantors with the trustee, in trust, of any amount, in such currency or currencies, currency unit or units or composite currency or currencies in which those debt securities are payable at stated maturity, or Government Obligations, or both, applicable to those debt securities which through the scheduled payment of principal and interest in accordance with their terms will provide money in an amount sufficient, based on a certification by officers of the Operating Partnership, to pay the principal of and premium, if any, and interest on such debt securities, and any mandatory sinking fund or analogous payments thereon, on the scheduled due dates.

This trust may only be established if, among other conditions, the Operating Partnership has delivered to the trustee an opinion of counsel to the effect that the holders of the debt securities will not recognize income, gain or loss for U.S. federal income tax purposes as a result of legal defeasance or covenant defeasance, as the case may be, and will be subject to U.S. federal income tax on the same amounts, in the same manner and at the same times as would have been the case if legal defeasance or covenant defeasance, as the case may be, had not occurred, and the opinion of counsel, in the case of legal defeasance, must refer to and be based upon a ruling of the Internal Revenue Service or a change in applicable U.S. federal income tax law occurring after the date of the indenture.

In the event the Operating Partnership effects covenant defeasance with respect to the debt securities of any series and those debt securities are declared due and payable because of the occurrence of any event of default other than an event of default described in clause (4) under "Events of Default, Notice and Waiver" with respect to the covenants described under "Covenants" (which would no longer be applicable to those debt securities) or described in clause (7) under "Events of Default, Notice and Waiver" with respect to any other covenant as to which there has been covenant defeasance, the amount in the currency, currency unit or composite currency in which those debt securities are payable, and Government Obligations on deposit with the trustee, will be sufficient to pay amounts due on those debt securities at the time of their stated maturity but may not be sufficient to pay amounts due on those debt securities at the time of the acceleration resulting from such event of default. However, the Operating Partnership and the guarantors would remain liable to make payment of those amounts due at the time of acceleration.

The applicable prospectus supplement may further describe the provisions, if any, permitting legal defeasance or covenant defeasance, including any modifications to the provisions described above, with respect to the debt securities of a particular series.

The terms and conditions, if any, upon which the debt securities of any series will be subordinated to other indebtedness of the Operating Partnership, including the debt securities of other series, will be set forth in the applicable prospectus supplement. These terms will include a description of the indebtedness ranking senior to the debt securities of that series, the restrictions on payments to the holders of the debt securities of that series while a default with respect to the senior indebtedness is continuing, the restrictions, if any, on payments to the holders of the debt securities of that series following an event of default, and provisions requiring holders of the debt securities of that series to remit certain payments to holders of senior indebtedness.

The debt securities of a series may be issued in whole or in part in the form of one or more securities in global form that will be deposited with, or on behalf of, a depository identified in the applicable prospectus supplement relating to that series. Global securities, if any, issued in the United States are expected to be deposited with The Depository Trust Company, or DTC, as depository. Unless otherwise indicated, global securities will be issued in fully registered form and in either temporary or permanent form. Unless the applicable prospectus supplement states otherwise, and until it is exchanged in whole or in part for the debt securities represented thereby, a global security may not be transferred except as a whole by the depository for that global security to a nominee of that depository or by a nominee of that depository to that depository or another nominee of such depository or by that depository or any nominee of that depository to a successor depository or any nominee of that successor.

The specific terms of the depository arrangement with respect to a series of debt securities will be described in the applicable prospectus supplement. We anticipate that, unless otherwise indicated in the applicable prospectus supplement, the following provisions will apply to depository arrangements.

The applicable prospectus supplement will state whether the global securities will be issued in certificated or book-entry form. If the global securities are to be issued in book-entry form, we expect that upon the issuance of a global security, the depository for the global security or its nominee will credit on its book-entry registration and transfer system the respective principal amounts of the individual debt securities represented by the global security to the accounts of persons that have accounts with such depository, or participants. These accounts will be designated by the underwriters, dealers or agents with respect to the debt securities. Ownership of beneficial interests in a global security will be limited to participants or persons that may hold interests through participants.

We expect that, for the global securities deposited with DTC, pursuant to procedures established by DTC, ownership of beneficial interests in any global security with respect to which DTC is the depository will be shown on, and the transfer of that ownership will be effected only through, records maintained by DTC or its nominee (with respect to beneficial interests of participants) and records of participants (with respect to beneficial interests of persons who hold through participants). None of the Operating Partnership, the guarantors, the trustee, any paying agent and the security registrar will have any responsibility or liability for any aspect of the records of DTC or for maintaining, supervising or reviewing any records of DTC or any of its participants relating to beneficial ownership interests in the debt securities. The laws of some states require that certain purchasers of securities take physical delivery of such securities in definitive form. These limits and laws may impair the ability to own, pledge or transfer beneficial interest in a global security.

Unless otherwise specified in the applicable prospectus supplement or the actual global security, so long as the depository for a global security or its nominee is the registered owner of the book-entry global security, the depository or that nominee, as the case may be, will be considered the sole owner or holder of the debt securities represented by that global security for all purposes under the applicable

indenture. Except as described below or in the applicable prospectus supplement or the global security, owners of beneficial interest in a global security will not be entitled to have any of the individual debt securities represented by the global security registered in their names, will not receive or be entitled to receive delivery of debt securities in definitive certificated form and will not be considered the owners or holders thereof under the applicable indenture. Beneficial owners of debt securities evidenced by a global security will not be considered the owners or holders thereof under the indenture for any purpose, including with respect to the giving of any direction, instructions or approvals to the trustee thereunder. Accordingly, each person owning a beneficial interest in a global security with respect to which DTC is the depository must rely on the procedures of DTC and, if that person is not a participant, on the procedures of the participant through which that person owns its interests, to exercise any rights of a holder under the applicable indenture. We understand that, under existing industry practice, if we request any action of holders or if an owner of a beneficial interest in a global security desires to give or take any action which a holder is entitled to give or take under the applicable indenture, DTC would authorize the participants holding the relevant beneficial interest to give or take that action, and the participants would authorize beneficial owners through the participants to give or take that action or would otherwise act upon the instructions of beneficial owners holding through them.

Payments of principal of and premium, if any, and interest on debt securities represented by a global security registered in the name of a depository or its nominee will be made to or at the direction of the depository or its nominee, as the case may be, as the registered owner of the global security under the indenture. Under the terms of the indenture, the Operating Partnership, the guarantors, the trustee, any paying agent and the security registrar may treat the persons in whose name debt securities, including a global security, are registered as the owners thereof for the purpose of receiving such payments. Consequently, none of the Operating Partnership, the guarantors, the trustee, any paying agent and the security registrar has or will have any responsibility or liability for the payment of those amounts to beneficial owners of debt securities (including principal, premium, if any, and interest). We believe, however, that it is currently the policy of DTC to immediately credit the accounts of relevant participants with payments, in amounts proportionate to their respective holdings of beneficial interests in the relevant global security as shown on the records of DTC or its nominee. Payments by participants to owners of beneficial interests in the global security held through participants will be governed by standing instructions and customary practices, as is the case with securities held for the account of customers in bearer form or registered in street name, and will be the responsibility of the participants. Redemption notices with respect to any debt securities represented by a global security will be sent to the depository or its nominee. If less than all of the debt securities of any series are to be redeemed, we expect the depository to determine the amount of the interest of each participant in the debt securities to be redeemed to be determined by lot. None of the Operating Partnership, the guarantors, the trustee, any paying agent and the security registrar for the debt securities will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in the global security for the debt securities or for maintaining any records with respect thereto.

None of the Operating Partnership, the guarantors, the trustee, any paying agent and the security registrar will be liable for any delay by the holders of a global security or the depository in identifying the beneficial owners of debt securities and the Operating Partnership, the guarantors and the trustee may conclusively rely on, and will be protected in relying on, instructions from the holder of a global security or the depository for all purposes. The rules applicable to DTC and its participants are on file with the SEC.

If a depository for any debt securities is at any time unwilling, unable or ineligible to continue as depository and a successor depository is not appointed by the Operating Partnership within 90 days, the Operating Partnership will issue definitive certificated debt securities in exchange for the global security

representing those debt securities. If an event of default has occurred and is continuing with respect to the debt securities of any series, the Operating Partnership will issue definitive certificated debt securities in exchange for the global security or securities representing the debt securities of such series. In addition, the Operating Partnership may at any time and in its sole discretion, subject to any limitations described in the applicable prospectus supplement or the global security relating to the debt securities, determine not to have any of the debt securities represented by one or more global securities and in such event will issue definitive certificated debt securities in exchange for the global security or securities representing the debt securities.

The debt securities of a series may also be issued in whole or in part in the form of one or more bearer global securities that will be deposited outside of the United States with a depository, or with a nominee for the depository, identified in the applicable prospectus supplement and/or global security. Any such bearer global securities may be issued in temporary or permanent form. The specific terms and procedures, including the specific terms of the depository arrangement, with respect to any portion of a series of debt securities to be represented by one or more bearer global securities will be described in the applicable prospectus supplement and/or global security.

The following are certain defined terms used in this prospectus and the indenture. We refer you to the indenture for the complete definition of all defined terms, as well as any other capitalized terms used in this prospectus or the applicable prospectus supplement for which no definition is provided (Section 101).

For purposes of the following definitions and the indenture generally, all calculations and determinations will be made in accordance with generally accepted accounting principles and will be based upon the consolidated financial statements of the Operating Partnership and its Subsidiaries prepared in accordance with generally accepted accounting principles.

"Subsidiary" means, as to any person, (a) any corporation more than 50% of whose stock of any class or classes having by the terms thereof ordinary voting power to elect a majority of the directors of such corporation (irrespective of whether or not at the time, any class or classes of stock of such corporation shall have or might have voting power by reason of the lapse of time or the happening of any contingency) is at the time owned by such person directly or indirectly through Subsidiaries, and (b) any partnership, association, joint venture, limited liability company, trust or other entity in which

such person directly or indirectly through Subsidiaries has more than a 50% equity interest or 50% Capital Percentage at any time. For the purpose of this definition, "Capital Percentage" means, with respect to the interest of CubeSmart, the Operating Partnership or one of its Subsidiaries in any partnership, association, joint venture, limited liability company, trust or other entity, the percentage interest of such partnership, association, joint venture, limited liability company, trust or other entity based on the aggregate amount of net capital contributed by CubeSmart, the Operating Partnership or such Subsidiary in such partnership, association, joint venture, limited liability company, trust or other entity at the time of determination relative to all capital contributions made in such partnership, association, joint venture, limited liability company, trust or other entity at such time of determination.

"United States Alien" means any corporation, partnership, individual or fiduciary that is, as to the United States, a foreign corporation, a nonresident alien individual, a nonresident fiduciary of a foreign estate or trust, or a foreign partnership one or more of the members of which is, as to the United States, a foreign corporation, a nonresident alien individual or a nonresident fiduciary of a foreign estate or trust.

Information about selling securityholders, where applicable, will be set forth in a prospectus supplement, in a post-effective amendment, or in filings we make with the SEC under the Exchange Act which are incorporated by reference.

The following discussion describes the material U.S. federal income tax considerations relating to the purchase, ownership and disposition of common shares and preferred shares of CubeSmart and debt securities of the Operating Partnership, and the qualification and taxation of CubeSmart as a REIT under the Code.

This discussion is not exhaustive of all possible tax considerations and does not provide a detailed discussion of any state, local or foreign tax considerations. The discussion does not address all aspects of taxation that may be relevant to particular investors in light of their personal investment or tax circumstances, or to certain types of investors that are subject to special treatment under the U.S. federal income tax laws, such as insurance companies, regulated investment companies, REITs, tax-exempt organizations (except to the limited extent discussed below under "Taxation of Tax-Exempt Shareholders"), financial institutions or broker-dealers, non-U.S. individuals and foreign corporations (except to the limited extent discussed below under "Taxation of Non-U.S. Shareholders"), an entity treated as a U.S. corporation on account of the inversion rules, and other persons subject to special tax rules. This summary deals only with investors who hold common shares or preferred shares of CubeSmart or debt securities of the Operating Partnership as "capital assets" within the meaning of Section 1221 of the Code. This discussion is not intended to be, and should not be construed as, tax advice.

The information in this summary is based on the Code, current, temporary and proposed Treasury regulations, the legislative history of the Code, current administrative interpretations and practices of the Internal Revenue Service, or the IRS, including its practices and policies as endorsed in private letter rulings, which are not binding on the IRS, and existing court decisions. Future legislation, regulations, administrative interpretations and court decisions could change current law or adversely affect existing interpretations of current law. Any change could apply retroactively. We have not obtained any rulings from the IRS concerning the tax treatment of the matters discussed in this summary. Therefore, it is possible that the IRS could challenge the statements in this summary, which do not bind the IRS or the courts, and that a court could agree with the IRS.

We urge you to consult your own tax advisor regarding the specific tax consequences to you of ownership of common shares or preferred shares of CubeSmart and debt securities of the Operating Partnership, and of CubeSmart's election to be taxed as a REIT. Specifically, you should consult your own tax advisor regarding the federal, state, local, foreign, and other tax consequences of such ownership and election, and regarding potential changes in applicable tax laws.

CubeSmart elected to be taxed as a REIT under the U.S. federal income tax laws beginning with its short taxable year ended December 31, 2004. CubeSmart believes that, beginning with such short taxable year, it has been organized and has operated in such a manner as to qualify for taxation as a REIT under the Code and intends to continue to operate in such a manner. However, there can be no assurance that CubeSmart has qualified or will remain qualified as a REIT.

CubeSmart's continued qualification and taxation as a REIT depend upon its ability to meet on a continuing basis, through actual annual operating results, certain qualification tests set forth in the U.S. federal income tax laws. Those qualification tests involve the percentage of income that CubeSmart earns from specified sources, the percentage of its assets that falls within specified categories, the diversity of its share ownership, and the percentage of its earnings that CubeSmart distributes. Accordingly, no assurance can be given that the actual results of CubeSmart's operations for any particular taxable year will satisfy such requirements. For a discussion of the tax consequences of its failure to qualify as a REIT, see "Requirements for Qualification—Failure to Qualify" below.

Pursuant to CubeSmart's declaration of trust, CubeSmart's board of trustees has the authority to make any tax elections on its behalf that, in its sole judgment, are in CubeSmart's best interest. This authority includes the ability to revoke or otherwise terminate CubeSmart's status as a REIT. CubeSmart's board of trustees has the authority under its declaration of trust to make these elections without the necessity of obtaining the approval of CubeSmart's shareholders. In addition, CubeSmart's board of trustees has the authority to waive any restrictions and limitations contained in its declaration of trust that are intended to preserve CubeSmart's status as a REIT during any period in which its board of trustees has determined not to pursue or preserve CubeSmart's status as a REIT.

The sections of the Code relating to qualification and operation as a REIT, and the U.S. federal income taxation of a REIT, are highly technical and complex. The following discussion sets forth only the material aspects of those sections. This summary is qualified in its entirety by the applicable Code provisions and the related rules and regulations.

If CubeSmart qualifies as a REIT, it generally will not be subject to federal income tax on the taxable income that it distributes to its shareholders. The benefit of that tax treatment is that it avoids the "double taxation," or taxation at both the corporate and shareholder levels, that generally results from owning shares in a corporation. However, CubeSmart will be subject to federal tax in the following circumstances:

In addition, we may be subject to a variety of taxes, including payroll taxes and state, local and foreign income, property and other taxes on our assets and operations. We could also be subject to tax in situations and on transactions not presently contemplated.

To qualify as a REIT, CubeSmart must elect to be treated as a REIT, and CubeSmart must meet various (a) organizational requirements, (b) gross income tests, (c) asset tests, and (d) annual distribution requirements.

Organizational Requirements. A REIT is a corporation, trust or association that meets each of the following requirements:

CubeSmart must meet requirements 1 through 4, 8 and 9 during its entire taxable year and must meet requirement 5 during at least 335 days of a taxable year of 12 months, or during a proportionate part of a taxable year of less than 12 months. CubeSmart's declaration of trust provides for restrictions regarding the ownership and transfer of its shares of beneficial interest that are intended to assist CubeSmart in continuing to satisfy requirements 5 and 6. However, these restrictions may not ensure that CubeSmart will, in all cases, be able to satisfy these requirements. The provisions of the declaration of trust restricting the ownership and transfer of its shares of beneficial interest are described in "Description of Our Shares—Restrictions on Ownership and Transfer."

For purposes of determining share ownership under requirement 6, an "individual" generally includes a supplemental unemployment compensation benefits plan, a private foundation, or a portion of a trust permanently set aside or used exclusively for charitable purposes. An "individual," however, generally does not include a trust that is a qualified employee pension or profit sharing trust under the U.S. federal income tax laws, and beneficiaries of such a trust will be treated as holding CubeSmart's shares in proportion to their actuarial interests in the trust for purposes of requirement 6. CubeSmart believes it has issued sufficient shares of beneficial interest with enough diversity of ownership to satisfy requirements 5 and 6 set forth above.

To monitor compliance with the share ownership requirements, CubeSmart is required to maintain records regarding the actual ownership of its shares. To do so, CubeSmart must demand written statements each year from the record holders of certain percentages of its shares in which the record holders are to disclose the actual owners of the shares (the persons required to include in gross income the dividends paid by us). A list of those persons failing or refusing to comply with this demand must be maintained as part of CubeSmart's records. Failure by CubeSmart to comply with these record-keeping requirements could subject CubeSmart to monetary penalties. If CubeSmart satisfies these requirements and has no reason to know that condition (6) is not satisfied, CubeSmart will be deemed to have satisfied such condition. A shareholder that fails or refuses to comply with the demand is required by Treasury regulations to submit a statement with its tax return disclosing the actual ownership of the shares and other information.

Qualified REIT Subsidiaries. A corporation that is a "qualified REIT subsidiary" is not treated as a corporation separate from its parent REIT. A "qualified REIT subsidiary" is a corporation, all of the capital stock of which is owned by the REIT and that has not elected to be a taxable REIT subsidiary. All assets, liabilities, and items of income, deduction, and credit of a "qualified REIT subsidiary" are treated as assets, liabilities, and items of income, deduction, and credit of the REIT. Thus, in applying the requirements described herein, any "qualified REIT subsidiary" that CubeSmart owns will be ignored, and all assets, liabilities, and items of income, deduction, and credit of such subsidiary will be treated as its assets, liabilities, and items of income, deduction, and credit.

Partnership Subsidiaries. An unincorporated domestic entity, such as a partnership or limited liability company that has a single owner, generally is not treated as an entity separate from its parent for U.S. federal income tax purposes. An unincorporated domestic entity with two or more owners is generally treated as a partnership for U.S. federal income tax purposes. In the case of a REIT that is a partner in a partnership, the REIT is treated as owning its proportionate share of the assets of the partnership and as earning its allocable share of the gross income of the partnership for purposes of the applicable REIT qualification tests. Thus, CubeSmart's proportionate share of the assets, liabilities and items of income of the Operating Partnership and any other partnership, joint venture, or limited liability company that is treated as a partnership for U.S. federal income tax purposes in which CubeSmart acquires an interest, directly or indirectly, is treated as CubeSmart's assets and gross income for purposes of applying the various REIT qualification requirements.

Taxable REIT Subsidiaries. A REIT is permitted to own up to 100% of the stock of one or more "taxable REIT subsidiaries." A taxable REIT subsidiary is a corporation subject to U.S. federal income tax, and state and local income tax where applicable, as a regular "C" corporation. The subsidiary and the REIT must jointly elect to treat the subsidiary as a taxable REIT subsidiary. In addition, if a taxable REIT subsidiary owns, directly or indirectly, securities representing 35% or more of the vote or value of a subsidiary corporation, that subsidiary will also be treated as a taxable REIT subsidiary. Several provisions regarding the arrangements between a REIT and its taxable REIT subsidiaries ensure that a taxable REIT subsidiary will be subject to an appropriate level of U.S. federal income taxation. For example, the taxable REIT subsidiary rules limit the deductibility of interest paid or accrued by a taxable REIT subsidiary to its parent REIT. Further, the rules impose a 100% excise tax on transactions between a taxable REIT subsidiary and its parent REIT or the REIT's tenants that are not conducted on an arm's-length basis, and, effective for taxable years beginning after December 31, 2015, on income imputed to a taxable REIT subsidiary, for services rendered to or on behalf of CubeSmart, the Operating Partnership, any qualified REIT subsidiary, or a Partnership Subsidiary. CubeSmart may engage in activities indirectly through a taxable REIT subsidiary that would jeopardize its REIT status if CubeSmart engaged in the activities directly. For example, a taxable REIT subsidiary of CubeSmart may provide services to unrelated parties which might produce income that does not qualify under the gross income tests described below. A taxable REIT subsidiary may also engage in other activities that, if conducted by CubeSmart directly, could result in the receipt of non-qualified

income or the ownership of non-qualified assets or the imposition of the 100% tax on income from prohibited transactions. See description below under "Prohibited Transactions."

Gross Income Tests. CubeSmart must satisfy two gross income tests annually to maintain its qualification as a REIT. First, at least 75% of its gross income for each taxable year must consist of defined types of income that CubeSmart derives, directly or indirectly, from investments relating to real property or mortgages on real property or qualified temporary investment income. Qualifying income for purposes of that 75% gross income test generally includes:

Second, in general, at least 95% of CubeSmart's gross income for each taxable year must consist of income that is qualifying income for purposes of the 75% gross income test, other types of interest and dividends (including dividends from its taxable REIT subsidiaries), gain from the sale or disposition of stock or securities, or any combination of these.

Gross income from the sale of property that CubeSmart holds primarily for sale to customers in the ordinary course of business is excluded from both the numerator and the denominator in both income tests. See "Prohibited Transactions." In addition, certain gains from hedging transactions and certain foreign currency gains will be excluded from both the numerator and the denominator for purposes of one or both of the income tests. See "Hedging Transactions," and "Foreign Currency Gain."

Rents from Real Property. Rent that CubeSmart receives from its real property will qualify as "rents from real property," which is qualifying income for purposes of the 75% and 95% gross income tests, only if the following conditions are met:

First, the rent must not be based in whole or in part on the income or profits of any person. Participating rent, however, will qualify as "rents from real property" if it is based on percentages of receipts or sales and the percentages are fixed at the time the leases are entered into, are not renegotiated during the term of the leases in a manner that has the effect of basing percentage rent on income or profits, and conform with normal business practice.

Second, CubeSmart must not own, actually or constructively, 10% or more of the stock of any corporate tenant or the assets or net profits of any tenant, referred to as a related-party tenant, other than a taxable REIT subsidiary. The constructive ownership rules generally provide that, if 10% or

more in value of its shares is owned, directly or indirectly, by or for any person, CubeSmart is considered as owning the stock owned, directly or indirectly, by or for such person. CubeSmart does not own any stock or any assets or net profits of any tenant directly. However, because the constructive ownership rules are broad and it is not possible to monitor continually direct and indirect transfers of its shares, no absolute assurance can be given that such transfers or other events of which CubeSmart has no knowledge will not cause CubeSmart to own constructively 10% or more of a tenant (or a subtenant, in which case only rent attributable to the subtenant is disqualified) other than a taxable REIT subsidiary at some future date.

Under an exception to the related-party tenant rule described in the preceding paragraph, rent that CubeSmart receives from a taxable REIT subsidiary will qualify as "rents from real property" as long as (1) at least 90% of the leased space in the property is leased to persons other than taxable REIT subsidiaries and related-party tenants, and (2) the amount paid by the taxable REIT subsidiary to rent space at the property is substantially comparable to rents paid by other tenants of the property for comparable space. The "substantially comparable" requirement must be satisfied when the lease is entered into, when it is extended, and when the lease is modified, if the modification increases the rent paid by the taxable REIT subsidiary. If the requirement that at least 90% of the leased space in the related property is rented to unrelated tenants is met when a lease is entered into, extended, or modified, such requirement will continue to be met as long as there is no increase in the space leased to any taxable REIT subsidiary or related-party tenant. Any increased rent attributable to a modification of a lease with a taxable REIT subsidiary in which CubeSmart owns directly or indirectly more than 50% of the voting power or value of the stock, or a controlled taxable REIT subsidiary, will not be treated as "rents from real property."

Third, the rent attributable to the personal property leased in connection with a lease of real property must not be greater than 15% of the total rent received under the lease. The rent attributable to personal property under a lease is the amount that bears the same ratio to total rent under the lease for the taxable year as the average of the fair market values of the leased personal property at the beginning and at the end of the taxable year bears to the average of the aggregate fair market values of both the real and personal property covered by the lease at the beginning and at the end of such taxable year, or the personal property ratio. With respect to each of its leases, CubeSmart believes that the personal property ratio generally is less than 15%. Where that is not, or may in the future not be, the case, CubeSmart believes that any income attributable to personal property will not jeopardize its ability to qualify as a REIT. There can be no assurance, however, that the IRS would not challenge CubeSmart's calculation of a personal property ratio, or that a court would not uphold such assertion. If such a challenge were successfully asserted, CubeSmart could fail to satisfy the 75% or 95% gross income test and thus lose its REIT status.

Fourth, CubeSmart cannot furnish or render non-customary services to the tenants of its properties, or manage or operate its properties, other than through an independent contractor who is adequately compensated and from whom CubeSmart does not derive or receive any income. However, CubeSmart need not provide services through an "independent contractor," but instead may provide services directly to its tenants, if the services are "usually or customarily rendered" in connection with the rental of space for occupancy only and are not considered to be provided for the tenants' convenience. In addition, CubeSmart may provide a minimal amount of "non-customary" services to the tenants of a property, other than through an independent contractor, as long as its income from the services does not exceed 1% of its income from the related property.

Finally, CubeSmart may own up to 100% of the stock of one or more taxable REIT subsidiaries, which may provide non-customary services to CubeSmart's tenants without tainting CubeSmart's rents from the related properties. CubeSmart has not performed, and does not intend to perform, any services other than customary ones for its tenants, other than services provided through independent contractors or taxable REIT subsidiaries.

Tenants may be required to pay, in addition to base rent, reimbursements for certain amounts CubeSmart is obligated to pay to third parties (such as a lessee's proportionate share of a property's operational or capital expenses), penalties for nonpayment or late payment of rent or additions to rent. These and other similar payments should qualify as "rents from real property." To the extent they do not, they should be treated as interest that qualifies for the 95% gross income test.

If a portion of the rent CubeSmart receives from a property does not qualify as "rents from real property" because the rent attributable to personal property exceeds 15% of the total rent for a taxable year, the portion of the rent attributable to personal property will not be qualifying income for purposes of either the 75% or 95% gross income test. Thus, if rent attributable to personal property, plus any other income that is nonqualifying income for purposes of the 95% gross income test, during a taxable year exceeds 5% of its gross income during the year, CubeSmart would lose its REIT status, unless CubeSmart qualified for certain statutory relief provisions. By contrast, in the following circumstances, none of the rent from a lease of property would qualify as "rents from real property": (1) the rent is considered based on the income or profits of the tenant; (2) the lessee is a related-party tenant or fails to qualify for the exception to the related-party tenant rule for qualifying taxable REIT subsidiaries; or (3) CubeSmart furnishes non-customary services to the tenants of the property, or manages or operates the property, other than through a qualifying independent contractor or a taxable REIT subsidiary. In any of these circumstances, CubeSmart could lose its REIT status, unless CubeSmart qualified for certain statutory relief provisions, because it would be unable to satisfy either the 75% or 95% gross income test.

Interest. The term "interest" generally does not include any amount received or accrued, directly or indirectly, if the determination of the amount depends in whole or in part on the income or profits of any person. However, an amount received or accrued generally will not be excluded from the term "interest" solely because it is based on a fixed percentage or percentages of receipts or sales. Furthermore, to the extent that interest from a loan that is based on the profit or net cash proceeds from the sale of the property securing the loan constitutes a "shared appreciation provision," income attributable to such participation feature will be treated as gain from the sale of the secured property.

Prohibited Transactions. A REIT will incur a 100% tax on the net income derived from any sale or other disposition of property, other than foreclosure property, that the REIT holds primarily for sale to customers in the ordinary course of a trade or business. Whether a REIT holds an asset "primarily for sale to customers in the ordinary course of a trade or business" depends, however, on the facts and circumstances in effect from time to time, including those related to a particular asset. A safe harbor to the characterization of the sale of property by a REIT as a prohibited transaction and the 100% prohibited transaction tax is available if the following requirements are met:

CubeSmart intends to hold properties for investment with a view to long-term appreciation, to engage in the business of acquiring, developing, owning and operating properties, and to make occasional sales of properties as are consistent with its investment objective. CubeSmart cannot assure you, however, that it can comply with the safe-harbor provisions that would prevent the imposition of the 100% tax or that it will avoid owning property that may be characterized as property held "primarily for sale to customers in the ordinary course of a trade or business." The 100% tax does not apply to gains from the sale of property that is held through a taxable REIT subsidiary or other taxable corporation, although such income will be subject to tax in the hands of that corporation at regular corporate tax rates. CubeSmart may, therefore, form or acquire a taxable REIT subsidiary to hold and dispose of those properties it concludes may not fall within the safe-harbor provisions.

Foreclosure Property. CubeSmart will be subject to tax at the maximum corporate rate on any net income from foreclosure property, other than income that otherwise would be qualifying income for purposes of the 75% gross income test. "Foreclosure property" is any real property, including interests in real property, and any personal property incident to such real property:

A REIT will not be considered to have foreclosed on a property where the REIT takes control of the property as a mortgagee-in-possession and cannot receive any profit or sustain any loss except as a creditor of the mortgagor. Property generally ceases to be foreclosure property at the end of the third taxable year following the taxable year in which the REIT acquired the property (or longer if an extension is granted by the Secretary of the Treasury). This period (as extended, if applicable) terminates, and foreclosure property ceases to be foreclosure property on the first day:

Any gain from the sale of property for which a foreclosure property election has been made will not be subject to the 100% tax on gains from prohibited transactions described above, even if the property is held primarily for sale to customers in the ordinary course of a trade or business. Income and gain from foreclosure property are qualifying income for the 75% and 95% gross income tests.

Hedging Transactions. From time to time, CubeSmart enters into hedging transactions with respect to its assets or liabilities. CubeSmart's hedging activities may include entering into interest rate swaps, caps, and floors, options to purchase such items, and futures and forward contracts. Income and gain from "hedging transactions" will be excluded from gross income for purposes of both the 75% and 95% gross income tests. A "hedging transaction" means either (1) any transaction entered into in the normal course of its trade or business primarily to manage the risk of interest rate, price changes, or currency fluctuations with respect to borrowings made or to be made, or ordinary obligations incurred or to be incurred, to acquire or carry real estate assets or (2) any transaction entered into primarily to manage the risk of currency fluctuations with respect to any item of income or gain that would be qualifying income under the 75% or 95% gross income test (or any property which generates such income or gain). CubeSmart will be required to clearly identify any such hedging transaction before the close of the day on which it was acquired, originated, or entered into and to satisfy other identification requirements. No assurance can be given that its hedging activities will not give rise to income that does not qualify for purposes of either or both of the gross income tests, and will not adversely affect CubeSmart's ability to satisfy the REIT qualification requirements.

Effective for taxable years beginning after December 31, 2015, if CubeSmart has entered into a hedging transaction described in (1) or (2), and a portion of the hedged indebtedness or property is extinguished or disposed of and, in connection with such extinguishment or disposition, CubeSmart enters into a new clearly identified hedging transaction, or a New Hedge, income from the applicable hedge and income from the New Hedge (including gain from the disposition of such New Hedge) will not be treated as gross income for purposes of the 95% and 75% gross income tests.

Foreign Currency Gain. Certain foreign currency gains will be excluded from gross income for purposes of one or both of the gross income tests. "Real estate foreign exchange gain" will be excluded from gross income for purposes of the 75% gross income test. Real estate foreign exchange gain generally includes foreign currency gain attributable to any item of income or gain that is qualifying income for purposes of the 75% gross income test, foreign currency gain attributable to the acquisition or ownership of (or becoming or being the obligor under) obligations secured by mortgages on real property or on interests in real property and certain foreign currency gain attributable to certain "qualified business units" of a REIT. "Passive foreign exchange gain" will be excluded from gross income for purposes of the 95% gross income test. Passive foreign exchange gain generally includes real estate foreign exchange gain as described above, and also includes foreign currency gain attributable to any item of income or gain that is qualifying income for purposes of the 95% gross income test and foreign currency gain attributable to the acquisition or ownership of (or becoming or being the obligor under) debt obligations. Because passive foreign exchange gain includes real estate foreign exchange gain, real estate foreign exchange gain is excluded from gross income for purposes of both the 75% and 95% gross income test. These exclusions for real estate foreign exchange gain and passive foreign exchange gain do not apply to foreign currency gain derived from dealing, or engaging in substantial and regular trading, in securities. Such gain is treated as nonqualifying income for purposes of both the 75% and 95% gross income tests.

Failure to Satisfy Gross Income Tests. If CubeSmart fails to satisfy one or both of the gross income tests for any taxable year, CubeSmart nevertheless may qualify as a REIT for that year if it qualifies for relief under certain provisions of the U.S. federal income tax laws. Those relief provisions will be available if:

CubeSmart cannot predict, however, whether any failure to meet these tests will qualify for the relief provisions. As discussed above in "Taxation of CubeSmart as a REIT," even if the relief provisions apply, CubeSmart would incur a 100% tax on the gross income attributable to the greater of (1) the amount by which it fails the 75% gross income test, or (2) the excess of 95% of its gross income over the amount of gross income qualifying under the 95% gross income test, multiplied, in either case, by a fraction intended to reflect its profitability.

Asset Tests. To maintain its qualification as a REIT, CubeSmart also must satisfy the following asset tests at the end of each quarter of each taxable year.

Second, of CubeSmart's investments not included in the 75% asset class, the value of its interest in any one issuer's securities may not exceed 5% of the value of its total assets, or the 5% asset test.

Third, of CubeSmart's investments not included in the 75% asset class, CubeSmart may not own more than 10% of the voting power or value of any one issuer's outstanding securities, or the 10% vote test and 10% value test, respectively.

Fourth, not more than 25% (20% for taxable years beginning after December 31, 2017) of the value of CubeSmart's assets may be represented by securities of one or more taxable REIT subsidiaries.

Fifth, effective for taxable years beginning after December 31, 2015, not more than 25% of the value of CubeSmart's total assets may be represented by "nonqualified publicly offered REIT debt

instruments." "Nonqualified publicly offered REIT debt instruments" are debt instruments issued by publicly offered REITs that are not secured by a mortgage on real property.

For purposes of the 5% asset test, the 10% vote test and 10% value test, the term "securities" does not include stock in another REIT, equity or debt securities of a qualified REIT subsidiary or taxable REIT subsidiary, mortgage loans that constitute real estate assets, or equity interests in a partnership. The term "securities," however, generally includes debt securities issued by a partnership or another REIT, except that for purposes of the 10% value test, the term "securities" does not include:

For purposes of the 10% value test, its proportionate share of the assets of a partnership is its proportionate interest in any securities issued by the partnership, without regard to the securities described in the last two bullet points above.

Failure to Satisfy Asset Tests. CubeSmart will monitor the status of its assets for purposes of the various asset tests and will manage its portfolio in order to comply at all times with such tests. If CubeSmart fails to satisfy the asset tests at the end of a calendar quarter, it would not lose its REIT status if:

If the failure to satisfy the asset tests results from an acquisition of securities or other property during a quarter, the failure can be cured by disposition of sufficient nonqualifying assets within 30 days after the close of that quarter. CubeSmart intends to maintain adequate records of the value of its assets to ensure compliance with the asset tests, and to take such other action within 30 days after the close of any quarter as may be required to cure any noncompliance. However, there can be no assurance that such other action will always be successful. If CubeSmart fails to cure any noncompliance with the asset tests within such time period, its status as a REIT would be lost.

In the event that, at the end of any calendar quarter, CubeSmart violates the 5% asset test, the 10% vote test or the 10% value test described above, CubeSmart will not lose its REIT status if (i) the failure is de minimis (up to the lesser of 1% of its assets or $10 million) and (ii) CubeSmart disposes of assets or otherwise complies with the asset tests within six months after the last day of the quarter in which it identifies such failure. In the event the failure to meet the asset test is more than de minimis, CubeSmart will not lose its REIT status if (i) the failure was due to reasonable cause and not to willful neglect, (ii) CubeSmart files a description of each asset causing the failure with the IRS, (iii) CubeSmart disposes of assets or otherwise complies with the asset tests within six months after the last day of the quarter in which CubeSmart identifies the failure, and (iv) CubeSmart pays a tax equal to the greater of $50,000 or 35% of the net income from the nonqualifying assets during the period in which it failed to satisfy the asset tests.

Annual Distribution Requirements. Each taxable year, CubeSmart must distribute dividends, other than capital gain dividends and deemed distributions of retained capital gain, to its shareholders in an aggregate amount not less than the sum of

Generally, CubeSmart must pay such distributions in the taxable year to which they relate, or in the following taxable year if either (a) CubeSmart declares the distribution before it timely files its U.S. federal income tax return for the year and pays the distribution on or before the first regular dividend payment date after such declaration or (b) CubeSmart declares the distribution in October, November, or December of the taxable year, payable to shareholders of record on a specified day in any such month, and CubeSmart actually pays the dividend before the end of January of the following year. In both instances, these distributions relate to its prior taxable year for purposes of the 90% distribution requirement.

In order for distributions to be counted towards CubeSmart's distribution requirement, and to provide a tax deduction to CubeSmart, for taxable years ending on or before December 31, 2014, they must not be "preferential dividends." A dividend is not a preferential dividend if it is pro rata among all outstanding shares within a particular class, and is in accordance with the preferences among the different classes of shares as set forth in CubeSmart's organizational documents. For all subsequent taxable years, so long as CubeSmart continues to be a "publicly offered REIT," the preferential dividend rule will not apply.

To the extent that CubeSmart distributes at least 90%, but less than 100%, of its net taxable income, CubeSmart will be subject to tax at ordinary corporate tax rates on the retained portion. In addition, CubeSmart may elect to retain, rather than distribute, its net long-term capital gains and pay

tax on such gains. In this case, CubeSmart would elect to have its shareholders include their proportionate share of such undistributed long-term capital gains in their income and receive a corresponding credit for their proportionate share of the tax paid by us. CubeSmart's shareholders would then increase their adjusted basis in their CubeSmart shares by the difference between the amount included in their long-term capital gains and the tax deemed paid with respect to their shares.

If CubeSmart fails to distribute during a calendar year, or by the end of January of the following calendar year in the case of distributions with declaration and record dates falling in the last three months of the calendar year, at least the sum of:

It is possible that, from time to time, CubeSmart may experience timing differences between the actual receipt of income and actual payment of deductible expenses and the inclusion of that income and deduction of such expenses in arriving at its REIT taxable income. For example, because CubeSmart may deduct capital losses only to the extent of its capital gains, its REIT taxable income may exceed its economic income. Further, it is possible that, from time to time, CubeSmart may be allocated a share of net capital gain from a partnership in which CubeSmart owns an interest attributable to the sale of depreciated property that exceeds its allocable share of cash attributable to that sale. Although several types of non-cash income are excluded in determining the annual distribution requirement, CubeSmart will incur corporate income tax and the 4% nondeductible excise tax with respect to those non-cash income items if CubeSmart does not distribute those items on a current basis. As a result of the foregoing, CubeSmart may have less cash than is necessary to distribute all of its taxable income and thereby avoid corporate income tax and the 4% nondeductible excise tax imposed on certain undistributed income. In such a situation, CubeSmart may issue additional common or preferred shares, CubeSmart may borrow or may cause the Operating Partnership to arrange for short-term or possibly long-term borrowing to permit the payment of required distributions, or CubeSmart may pay dividends in the form of taxable in-kind distributions of property, including potentially, its shares.

Under certain circumstances, CubeSmart may be able to correct a failure to meet the distribution requirement for a year by paying "deficiency dividends" to its shareholders in a later year. CubeSmart may include such deficiency dividends in its deduction for dividends paid for the earlier year. Although CubeSmart may be able to avoid income tax on amounts distributed as deficiency dividends, CubeSmart will be required to pay interest to the IRS based upon the amount of any deduction it takes for deficiency dividends.

If CubeSmart were to fail to qualify as a REIT in any taxable year and no relief provision applied, CubeSmart would have the following consequences: CubeSmart would be subject to U.S. federal income tax and any applicable alternative minimum tax at regular corporate rates applicable to regular C corporations on its taxable income, determined without reduction for amounts distributed to

shareholders. CubeSmart would not be required to make any distributions to shareholders. Unless CubeSmart qualified for relief under specific statutory provisions, it would not be permitted to elect taxation as a REIT for the four taxable years following the year during which CubeSmart ceased to qualify as a REIT.

If CubeSmart fails to satisfy one or more requirements for REIT qualification, other than the gross income tests and the asset tests, CubeSmart could avoid disqualification if its failure is due to reasonable cause and not to willful neglect and CubeSmart pays a penalty of $50,000 for each such failure. In addition, there are relief provisions for a failure of the gross income tests and asset tests, as described in "Requirements for Qualification—Gross Income Tests" and "Requirements for Qualification—Asset Tests." It is not possible to state whether in all circumstances CubeSmart would be entitled to such statutory relief.

We may be subject to taxation by various states and localities, including those in which we transact business or own property. The state and local tax treatment in such jurisdictions may differ from the U.S. federal income tax treatment described above.

Tax Aspects of Investments in the Operating Partnership and Subsidiary Partnerships

The following discussion summarizes certain U.S. federal income tax considerations applicable to CubeSmart's direct or indirect investment in its Operating Partnership and any subsidiary partnerships or limited liability companies we form or acquire that are treated as partnerships for U.S. federal income tax purposes, each individually referred to as a "Partnership" and, collectively, as "Partnerships." The following discussion does not address state or local tax laws or any federal tax laws other than income tax laws.

Classification as Partnerships. CubeSmart is required to include in its income its distributive share of each Partnership's income and to deduct its distributive share of each Partnership's losses but only if such Partnership is classified for U.S. federal income tax purposes as a partnership (or an entity that is disregarded for U.S. federal income tax purposes if the entity has only one owner or member), rather than as a corporation or an association taxable as a corporation.

An organization with at least two owners or members will be classified as a partnership, rather than as a corporation, for U.S. federal income tax purposes if it:

Under the check-the-box regulations, an unincorporated domestic entity with at least two owners or members may elect to be classified either as an association taxable as a corporation or as a partnership. If such an entity does not make an election, it generally will be treated as a partnership for U.S. federal income tax purposes. We intend that each Partnership will be classified as a partnership for U.S. federal income tax purposes (or else a disregarded entity where there are not at least two separate beneficial owners).

A publicly traded partnership is a partnership whose interests are traded on an established securities market or are readily tradable on a secondary market (or a substantial equivalent). A publicly traded partnership is generally treated as a corporation for U.S. federal income tax purposes, but will not be so treated if, for each taxable year beginning after December 31, 1987 in which it was classified as a publicly traded partnership, at least 90% of the partnership's gross income consisted of specified passive income, including real property rents (which includes rents that would be qualifying income for

purposes of the 75% gross income test, with certain modifications that make it easier for the rents to qualify for the 90% passive income exception), gains from the sale or other disposition of real property, interest, and dividends, or the 90% passive income exception.

Treasury regulations provide limited safe harbors from treatment as a publicly traded partnership. Pursuant to one of those safe harbors, or the private placement exclusion, interests in a partnership will not be treated as readily tradable on a secondary market or the substantial equivalent thereof if (1) all interests in the partnership were issued in a transaction or transactions that were not required to be registered under the Securities Act of 1933, as amended, and (2) the partnership does not have more than 100 partners at any time during the partnership's taxable year. For the determination of the number of partners in a partnership, a person owning an interest in a partnership, grantor trust, or S corporation that owns an interest in the partnership is treated as a partner in the partnership only if (1) substantially all of the value of the owner's interest in the entity is attributable to the entity's direct or indirect interest in the partnership and (2) a principal purpose of the use of the entity is to permit the partnership to satisfy the 100-partner limitation. CubeSmart believes that each Partnership should qualify for the private placement exclusion.

We have not requested, and do not intend to request, a ruling from the IRS that the Partnerships will be classified as partnerships (or disregarded entities, if the entity has only one owner or member) for U.S. federal income tax purposes. If for any reason a Partnership were taxable as a corporation, rather than as a partnership, for U.S. federal income tax purposes, CubeSmart may not be able to qualify as a REIT, unless it qualifies for certain relief provisions. See "Requirements for Qualification—Gross Income Tests" and "Requirements for Qualification—Asset Tests." In addition, any change in a Partnership's status for tax purposes might be treated as a taxable event, in which case CubeSmart might incur tax liability without any related cash distribution. See "Requirements for Qualification—Annual Distribution Requirements." Further, items of income and deduction of such Partnership would not pass through to its partners, and its partners would be treated as shareholders for tax purposes. Consequently, such Partnership would be required to pay income tax at corporate rates on its net income, and distributions to its partners would constitute dividends that would not be deductible in computing such Partnership's taxable income.

Partners, Not the Partnerships, Subject to Tax. A partnership is not a taxable entity for U.S. federal income tax purposes, except that, for tax years beginning after December 31, 2017, a partnership is liable for paying tax assessed pursuant to an audit adjustment unless the partnership elects to pass-through such audit adjustments to its partners. CubeSmart will therefore take into account its allocable share of each Partnership's income, gains, losses, deductions, and credits for each taxable year of the Partnership ending with or within CubeSmart's taxable year, even if CubeSmart receives no distribution from the Partnership for that year or a distribution less than CubeSmart's share of taxable income. Similarly, even if CubeSmart receives a distribution, CubeSmart may not be taxed on such distribution if the distribution does not exceed its adjusted tax basis in its interest in the distributing Partnership.

Partnership Allocations. Although a partnership agreement generally will determine the allocation of income and losses among partners, allocations will be disregarded for tax purposes if they do not comply with the provisions of the U.S. federal income tax laws governing partnership allocations. If an allocation is not recognized for U.S. federal income tax purposes, the item subject to the allocation will be reallocated in accordance with the partners' interests in the partnership, which will be determined by taking into account all of the facts and circumstances relating to the economic arrangement of the partners with respect to such item.

Tax Allocations With Respect to Contributed Properties. Income, gain, loss, and deduction attributable to (a) appreciated or depreciated property that is contributed to a partnership in exchange for an interest in the partnership or (b) property revalued on the books of a partnership must be

allocated in a manner such that each of a contributing partner or the partners at the time of a book revaluation, as applicable, are charged with, or benefits from, respectively, the unrealized gain or unrealized loss associated with the property at the time of the contribution. The amount of such unrealized gain or unrealized loss, referred to as "built-in gain" or "built-in loss," is generally equal to the difference between the fair market value of the contributed or revalued property at the time of contribution or revaluation and the adjusted tax basis of such property at that time, referred to as a book-tax difference. Such allocations are solely for U.S. federal income tax purposes and do not affect the book capital accounts or other economic or legal arrangements among the partners. The U.S. Treasury Department has issued regulations requiring partnerships to use a "reasonable method" for allocating items with respect to which there is a book-tax difference and outlining several reasonable allocation methods. Unless we, as general partner, select a different method, the Operating Partnership will use the traditional method for allocating items with respect to which there is a book-tax difference. Depending upon the method chosen, (1) CubeSmart's tax depreciation deductions attributable to those properties may be lower than they would have been if the partnership had acquired those properties for cash and (2) in the event of a sale of such properties, CubeSmart could be allocated gain in excess of its corresponding economic or book gain. These allocations may cause CubeSmart to recognize taxable income in excess of cash proceeds received by us, which might adversely affect CubeSmart's ability to comply with the REIT distribution requirements or result in CubeSmart's shareholders recognizing additional dividend income without an increase in distributions.

Depreciation. Some assets in our Partnerships include appreciated property contributed by its partners. Assets contributed to a Partnership in a tax-free transaction generally retain the same depreciation method and recovery period as they had in the hands of the partner who contributed them to the partnership. Accordingly, the Partnership's depreciation deductions for such contributed real property are based on the historic tax depreciation schedules for the properties prior to their contribution to the Operating Partnership.

Basis in Partnership Interest. CubeSmart's adjusted tax basis in any partnership interest it owns generally will be:

Loss allocated to CubeSmart in excess of its basis in a partnership interest will not be taken into account until CubeSmart again has basis sufficient to absorb the loss. A reduction of CubeSmart's share of partnership indebtedness will be treated as a constructive cash distribution to CubeSmart, and will reduce its adjusted tax basis in the partnership. Distributions, including constructive distributions, in excess of the basis of CubeSmart's partnership interest will constitute taxable income to CubeSmart. Such distributions and constructive distributions normally will be characterized as long-term capital gain.

Sale of a Partnership's Property. Generally, any gain realized by a Partnership on the sale of property that is a capital asset held for more than one year will be long-term capital gain, except for any portion of the gain treated as depreciation or cost recovery recapture. Any gain or loss recognized by a Partnership on the disposition of contributed or revalued properties will be allocated first to the partners who contributed the properties or who were partners at the time of revaluation, to the extent of their built-in gain or loss on those properties for U.S. federal income tax purposes. The partners'

built-in gain or loss on contributed or revalued properties is the difference between the partners' proportionate share of the book value of those properties and the partners' tax basis allocable to those properties at the time of the contribution or revaluation. Any remaining gain or loss recognized by the Partnership on the disposition of contributed or revalued properties, and any gain or loss recognized by the Partnership on the disposition of other properties, will be allocated among the partners in accordance with their percentage interests in the Partnership.

CubeSmart's share of any Partnership gain from the sale of inventory or other property held primarily for sale to customers in the ordinary course of the Partnership's trade or business will be treated as income from a prohibited transaction subject to a 100% tax. Income from a prohibited transaction may have an adverse effect on CubeSmart's ability to satisfy the gross income tests for REIT status. See "Requirements for Qualification—Gross Income Tests." CubeSmart does not presently intend to acquire or hold, or to allow any Partnership to acquire or hold, any property that is likely to be treated as inventory or property held primarily for sale to customers in the ordinary course of CubeSmart's, or the Partnership's, trade or business.

The term "U.S. shareholder" means a beneficial owner of CubeSmart common shares or preferred shares that, for U.S. federal income tax purposes, is:

If a partnership, entity or arrangement treated as a partnership for U.S. federal income tax purposes holds CubeSmart common shares or preferred shares, the U.S. federal income tax treatment of a partner in the partnership will generally depend on the status of the partner and the activities of the partnership. If you are a partner in a partnership holding CubeSmart common shares or preferred shares, you should consult your tax advisor regarding the consequences of the ownership and disposition of CubeSmart common shares or preferred shares by the partnership.

Taxation of U.S. Shareholders on Distributions. As long as CubeSmart qualifies as a REIT, a taxable U.S. shareholder will be required to take into account as ordinary income distributions made out of CubeSmart's current or accumulated earnings and profits that CubeSmart does not designate as capital gain dividends or retained long-term capital gain. A U.S. shareholder will not qualify for the dividends-received deduction generally available to corporations. Dividends paid to a U.S. shareholder generally will not qualify for the preferential tax rate for "qualified dividend income" (currently, a 20% maximum rate). Qualified dividend income generally includes dividends paid by domestic C corporations and certain qualified foreign corporations to most noncorporate U.S. shareholders. Because a REIT is not generally subject to U.S. federal income tax on the portion of its REIT taxable income distributed to its shareholders, CubeSmart's dividends generally will not be eligible for the preferential tax rate on qualified dividend income. As a result, CubeSmart's ordinary REIT dividends will be taxed at the higher rate applicable to ordinary income. Currently, the highest marginal

individual income tax rate on ordinary income is 39.6%. However, the preferential tax rate for qualified dividend income will apply to CubeSmart's ordinary REIT dividends, if any, that are (i) attributable to dividends received by CubeSmart from non-REIT corporations, such as our taxable REIT subsidiaries, and (ii) attributable to income upon which CubeSmart has paid corporate income tax (e.g., to the extent that CubeSmart distributes less than 100% of CubeSmart's taxable income). In general, to qualify for the preferential tax rate on qualified dividend income, a U.S. shareholder must hold CubeSmart common shares or preferred shares for more than 60 days during the 121-day period beginning on the date that is 60 days before the date on which the common shares or preferred shares become ex-dividend.

With respect to common shares, CubeSmart may distribute taxable dividends that are payable partly in cash and partly in CubeSmart common shares. Taxable U.S. shareholders receiving such dividends will be required to include the full amount of the dividends as ordinary income to the extent of CubeSmart's current and accumulated earnings and profits.

Any distribution CubeSmart declares in October, November, or December of any year that is payable to a U.S. shareholder of record on a specified date in any of those months will be treated as paid by CubeSmart and received by the U.S. shareholder on December 31 of the year, provided CubeSmart actually pays the distribution during January of the following calendar year.

Distributions to a U.S. shareholder which CubeSmart designates as capital gain dividends will generally be treated as long-term capital gain, without regard to the period for which the U.S. shareholder has held its common shares or preferred shares. In general, U.S. shareholders will be taxable on long-term capital gains at a maximum rate of 20%, except that the portion of such gain that is attributable to depreciation recapture will be taxable at the maximum rate of 25%. A corporate U.S. shareholder, however, may be required to treat up to 20% of certain capital gain dividends as ordinary income.

Effective for distributions paid or treated as being paid in taxable years beginning after December 31, 2015, the aggregate amount of dividends that CubeSmart may designate as "capital gain dividends" or "qualified dividend income" with respect to any taxable year may not exceed the dividends paid by CubeSmart with respect to such taxable year, including dividends that are paid in the following taxable year and treated as having been paid with respect to such taxable year by being (1) declared before CubeSmart timely files its tax return for such taxable year and (2) paid with or before the first regular dividend payment after such declaration.

CubeSmart may elect to retain and pay income tax on the net long-term capital gain that CubeSmart receives in a taxable year. In that case, a U.S. shareholder would be taxed on its proportionate share of CubeSmart's undistributed long-term capital gain. The U.S. shareholder would receive a credit or refund for its proportionate share of the tax CubeSmart paid. The U.S. shareholder would increase the basis in its common shares or preferred shares by the amount of its proportionate share of CubeSmart's undistributed long-term capital gain, minus its share of the tax CubeSmart paid.

A U.S. shareholder will not incur tax on a distribution in excess of CubeSmart's current and accumulated earnings and profits if the distribution does not exceed the adjusted basis of the U.S. shareholder's common shares or preferred shares. Instead, the distribution will reduce the adjusted basis of the shares, and any amount in excess of both CubeSmart's current and accumulated earnings and profits and the adjusted basis will be treated as capital gain, long-term capital gain if the shares have been held for more than one year, provided the shares are a capital asset in the hands of the U.S. shareholder.

Shareholders may not include in their individual income tax returns any of CubeSmart's net operating losses or capital losses. Instead, these losses are generally carried over by CubeSmart for potential offset against CubeSmart's future income. Taxable distributions from CubeSmart and gain

from the disposition of common shares or preferred shares will not be treated as passive activity income; and, therefore, shareholders generally will not be able to apply any "passive activity losses," such as losses from certain types of limited partnerships in which the shareholder is a limited partner, against such income. In addition, taxable distributions from CubeSmart and gain from the disposition of common shares or preferred shares generally will be treated as investment income for purposes of the investment interest limitations. CubeSmart will notify shareholders after the close of its taxable year as to the portions of the distributions attributable to that year that constitute ordinary income, return of capital, and capital gain.

Taxation of U.S. Shareholders on the Disposition of Common and Preferred Shares

In general, a U.S. shareholder who is not a dealer in securities must treat any gain or loss realized upon a taxable disposition of CubeSmart's common or preferred shares as long-term capital gain or loss if the U.S. shareholder has held the shares for more than one year, and otherwise as short-term capital gain or loss. In general, a U.S. shareholder will realize gain or loss in an amount equal to the difference between the sum of the fair market value of any property and the amount of cash received in such disposition and the U.S. shareholder's adjusted tax basis. A U.S. shareholder's adjusted tax basis generally will equal the U.S. shareholder's acquisition cost, increased by the excess of net capital gains deemed distributed to the U.S. shareholder less tax deemed paid by it and reduced by any returns of capital. However, a U.S. shareholder must treat any loss upon a sale or exchange of common or preferred shares held by such shareholder for six months or less as a long-term capital loss to the extent of capital gain dividends and any actual or deemed distributions from CubeSmart that such U.S. shareholder treats as long-term capital gain. All or a portion of any loss that a U.S. shareholder realizes upon a taxable disposition of common or preferred shares may be disallowed if the U.S. shareholder purchases other common shares or preferred shares within 30 days before or after the disposition.

If a U.S. shareholder recognizes a loss upon a subsequent disposition of CubeSmart shares in an amount that exceeds a prescribed threshold, it is possible that the provisions of Treasury regulations involving "reportable transactions" could apply, with a resulting requirement to separately disclose the loss generating transactions to the IRS. While these regulations are directed towards "tax shelters," they are written broadly, and apply to transactions that would not typically be considered tax shelters. Significant penalties apply for failure to comply with these requirements. You should consult your tax advisor concerning any possible disclosure obligation with respect to the receipt or disposition of CubeSmart shares, or transactions that might be undertaken directly or indirectly by us. Moreover, you should be aware that CubeSmart and other participants in transactions involving CubeSmart (including our advisors) might be subject to disclosure or other requirements pursuant to these regulations.

The tax-rate differential between capital gain and ordinary income for non-corporate taxpayers may be significant. A taxpayer generally must hold a capital asset for more than one year for gain or loss derived from its sale or exchange to be treated as long-term capital gain or loss. The highest marginal individual income tax rate is currently 39.6%. The maximum tax rate on long-term capital gain applicable to U.S. shareholders taxed at individual rates is 20%. The maximum tax rate on long-term capital gain from the sale or exchange of "section 1250 property" (i.e., generally, depreciable real property) is 25% to the extent the gain would have been treated as ordinary income if the property were "section 1245 property" (i.e., generally, depreciable personal property). CubeSmart generally may designate whether a distribution CubeSmart designates as capital gain dividends (and any retained capital gain that CubeSmart is deemed to distribute) is taxable to non-corporate shareholders at a 20% or 25% rate. The characterization of income as capital gain or ordinary income may affect the deductibility of capital losses. A non-corporate taxpayer may deduct capital losses not offset by capital gains against its ordinary income only up to a maximum of $3,000 annually. A non-corporate taxpayer may carry unused capital losses forward indefinitely. A corporate taxpayer must pay tax on its net capital gain at corporate ordinary-income rates. A corporate taxpayer may deduct capital losses only to the extent of capital gains, with unused losses carried back three years and forward five years.

Whenever we redeem any preferred shares, the treatment accorded to any redemption by us for cash (as distinguished from a sale, exchange or other disposition) of our preferred shares to a U.S. shareholder of such preferred shares can only be determined on the basis of the particular facts as to each holder at the time of redemption. In general, a U.S. shareholder of our preferred shares will recognize capital gain or loss measured by the difference between the amount received by the holder of such shares upon the redemption and such holder's adjusted tax basis in the preferred shares redeemed (provided the preferred shares are held as a capital asset) if such redemption (i) is "substantially disproportionate" with respect to the holder's interest in all classes of our shares under Section 302 (b)(2) of the Code, (ii) results in a "complete termination" of the holder's interest in all classes of our shares under Section 302(b)(3) of the Code, or (iii) is "not essentially equivalent to a dividend" with respect to the holder of the preferred shares under Section 302(b)(1) of the Code. In applying these tests, there must be taken into account not only the preferred shares being redeemed, but also such holder's ownership of other classes and series of our shares and any options (including stock purchase rights) to acquire any of the foregoing. The U.S. shareholder of our preferred shares also must take into account any such securities (including options) which are considered to be owned by such holder by reason of the constructive ownership rules set forth in Sections 318 and 302(c) of the Code.

If the U.S. shareholder of preferred shares owns (actually or constructively) none of our voting shares, or owns an insubstantial amount of our voting shares, based upon current law, it is probable that the redemption of preferred shares from such a holder would be considered to be "not essentially equivalent to a dividend." However, whether a distribution is "not essentially equivalent to a dividend" depends on all of the facts and circumstances, and a U.S. shareholder of our preferred shares intending to rely on any of the tests in this or the preceding paragraph at the time of redemption should consult its tax advisor to determine their application to its particular situation. If the redemption does not meet any of the tests under Section 302 of the Code, then the redemption proceeds received from our preferred shares will be treated as a distribution on our shares as described under "Taxation of U.S. Shareholders—Taxation of Taxable U.S. Shareholders—Taxation of U.S. Shareholders on Distributions." If the redemption of a holder's preferred shares is taxed as a dividend, the adjusted basis of such holder's redeemed preferred shares will be transferred to any other shares held by the holder. If the holder owns no other shares, under certain circumstances, such basis may be transferred to a related person, or it may be lost entirely.

With respect to a redemption of our preferred shares that is treated as a distribution with respect to our shares, which is not otherwise taxable as a dividend, the IRS has proposed Treasury regulations that would require any basis reduction associated with such a redemption to be applied on a share-by-share basis which could result in taxable gain with respect to some shares, even though the holder's aggregate basis for the shares would be sufficient to absorb the entire amount of the redemption distribution (in excess of any amount of such distribution treated as a dividend). Additionally, these proposed Treasury regulations would not permit the transfer of basis in the redeemed shares of the preferred shares to the remaining shares held (directly or indirectly) by the redeemed holder. Instead, the unrecovered basis in our preferred shares would be treated as a deferred loss to be recognized when certain conditions are satisfied. These proposed Treasury regulations would be effective for transactions that occur after the date the regulations are published as final Treasury regulations. There can, however, be no assurance as to whether, when, and in what particular form such proposed Treasury regulations will ultimately be finalized.

Except as provided below, a U.S. shareholder generally will not recognize gain or loss upon the conversion of our preferred shares into our common shares. Except as provided below, a U.S. shareholder's basis and holding period in the common shares received upon conversion generally will

be the same as those of the converted preferred shares (but the basis will be reduced by the portion of adjusted tax basis allocated to any fractional common share exchanged for cash). Any common shares received in a conversion that is attributable to accumulated and unpaid dividends on the converted preferred shares will be treated as a distribution on our shares as described above in "Taxation of U.S. Shareholders—Taxation of Taxable U.S. Shareholders—Taxation of U.S. Shareholders on Distributions." Cash received upon conversion in lieu of a fractional common share generally will be treated as a payment in a taxable exchange for such fractional common share, and gain or loss will be recognized on the receipt of cash in an amount equal to the difference between the amount of cash received and the adjusted tax basis allocable to the fractional common share deemed exchanged. This gain or loss will be long-term capital gain or loss if the U.S. shareholder has held the preferred shares for more than one year. See "—Taxation of U.S. Shareholders—Taxation of Taxable U.S. Shareholders—Taxation of U.S. Shareholders on the Disposition of Common and Preferred Shares." U.S. shareholders should consult with their tax advisors regarding the U.S. federal income tax consequences of any transaction by which such holder exchanges common shares received on a conversion of preferred shares for cash or other property.

Certain U.S. shareholders and U.S. Holders (as defined below) who are individuals, estates or trusts and whose income exceeds certain thresholds may be required to pay a 3.8% Medicare tax on "net investment income" which includes, among other things, dividends on shares, interest on debentures and capital gains from the sale or other disposition of shares or debentures, subject to certain exceptions. Prospective investors should consult their tax advisors regarding the effect, if any, of this legislation on their ownership and disposition of our common shares, preferred shares or debentures.

CubeSmart will report to its shareholders and to the IRS the amount of distributions CubeSmart pays during each calendar year and the amount of tax it withholds, if any. A shareholder may be subject to backup withholding at a rate of up to 28% with respect to distributions unless the holder:

A shareholder who does not provide CubeSmart with its correct taxpayer identification number also may be subject to penalties imposed by the IRS. In addition, CubeSmart may be required to withhold a portion of capital gain distributions to any shareholders who fail to certify their non-foreign status to CubeSmart. Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against the shareholder's income tax liability, provided the required information is timely furnished to the IRS.

Tax-exempt entities, including qualified employee pension and profit sharing trusts and individual retirement accounts and annuities, generally are exempt from U.S. federal income taxation. However, they are subject to taxation on their "unrelated business taxable income." While many investments in real estate generate unrelated business taxable income, the IRS has issued a ruling that dividend distributions from a REIT to an exempt employee pension trust do not constitute unrelated business taxable income so long as the exempt employee pension trust does not otherwise use the shares of the

REIT in an unrelated trade or business of the pension trust. Based on that ruling, amounts CubeSmart distributes to tax-exempt shareholders generally should not constitute unrelated business taxable income. However, if a tax-exempt shareholder were to finance its acquisition of common shares or preferred shares with debt, a portion of the income it received from CubeSmart would constitute unrelated business taxable income pursuant to the "debt-financed property" rules. Furthermore, social clubs, voluntary employee benefit associations, supplemental unemployment benefit trusts, and qualified group legal services plans that are exempt from taxation under special provisions of the U.S. federal income tax laws are subject to different unrelated business taxable income rules, which generally will require them to characterize distributions they receive from CubeSmart as unrelated business taxable income.

In certain circumstances, a qualified employee pension or profit-sharing trust that owns more than 10% of CubeSmart's shares of beneficial interest (by value) must treat a percentage of the dividends it receives from CubeSmart as unrelated business taxable income. Such percentage is equal to the gross income CubeSmart derives from an unrelated trade or business, determined as if CubeSmart were a pension trust, divided by its total gross income for the year in which it pays the dividends. This rule applies to a pension trust holding more than 10% of CubeSmart shares only if:

Certain restrictions on ownership and transfer of CubeSmart's shares should generally prevent a tax-exempt entity from owning more than 10% of the value of its shares, or CubeSmart from becoming a pension-held REIT.

Tax-exempt U.S. shareholders are urged to consult their tax advisors regarding the U.S. federal, state, local and foreign tax consequences of the acquisition, ownership and disposition of CubeSmart shares.

The term "non-U.S. shareholder" means a beneficial owner of CubeSmart common shares or preferred shares that is not a U.S. shareholder or a partnership (or an entity treated as a partnership for U.S. federal income tax purposes). The rules governing U.S. federal income taxation of non-U.S. shareholders are complex. This section is only a summary of such rules. We urge non-U.S. shareholders to consult their own tax advisors to determine the impact of federal, state, local and foreign income tax laws on ownership of common shares or preferred shares, including any reporting requirements.

Taxation of Distributions. A non-U.S. shareholder that receives a distribution which is not attributable to gain from CubeSmart's sale or exchange of a "United States real property interest," or USRPI (discussed below), and that CubeSmart does not designate a capital gain dividend or retained capital gain will recognize ordinary income to the extent that CubeSmart pays such distribution out of CubeSmart's current or accumulated earnings and profits.

A withholding tax equal to 30% of the gross amount of the distribution ordinarily will apply unless an applicable tax treaty reduces or eliminates the tax. However, a non-U.S. shareholder generally will be subject to U.S. federal income tax at graduated rates on any distribution treated as effectively connected with the non-U.S. shareholder's conduct of a U.S. trade or business, in the same manner as U.S. shareholders are taxed on distributions. A corporate non-U.S. shareholder may, in addition, be subject to the 30% branch profits tax with respect to that distribution. CubeSmart plans to withhold U.S. income tax at the rate of 30% on the gross amount of any distribution paid to a non-U.S. shareholder unless either:

A non-U.S. shareholder will not incur tax on a distribution in excess of CubeSmart's current and accumulated earnings and profits if the excess portion of such distribution does not exceed the adjusted basis of its common shares or preferred shares. Instead, the excess portion of the distribution will reduce the adjusted basis of such shares. A non-U.S. shareholder will be subject to tax on a distribution that exceeds both CubeSmart's current and accumulated earnings and profits and the adjusted basis of its shares, if the non-U.S. shareholder otherwise would be subject to tax on gain from the sale or disposition of common shares or preferred shares, as described below. Because CubeSmart generally cannot determine at the time CubeSmart makes a distribution whether the distribution will exceed CubeSmart's current and accumulated earnings and profits, CubeSmart normally will withhold tax on the entire amount of any distribution at the same rate as CubeSmart would withhold on a dividend. However, a non-U.S. shareholder may obtain a refund of amounts CubeSmart withholds if CubeSmart later determines that a distribution in fact exceeded CubeSmart's current and accumulated earnings and profits.

CubeSmart may be required to withhold 15% (increased from 10% effective February 17, 2016) of any distribution that exceeds CubeSmart's current and accumulated earnings and profits. Consequently, although CubeSmart intends to withhold at a rate of 30% on the entire amount of any distribution, to the extent CubeSmart does not do so, CubeSmart may withhold at a rate of 15% on any portion of a distribution not subject to withholding at a rate of 30%.

For any year in which CubeSmart qualifies as a REIT, except as discussed below with respect to 10% or less holders of regularly traded classes of shares, a non-U.S. shareholder will incur tax on distributions attributable to gain from CubeSmart's sale or exchange of a USRPI under the Foreign Investment in Real Property Tax Act of 1980, or FIRPTA. A USRPI includes certain interests in real property and shares in United States corporations at least 50% of whose assets consist of interests in real property. Under FIRPTA, a non-U.S. shareholder is taxed on distributions attributable to gain from sales of USRPIs as if the gain were effectively connected with the conduct of a U.S. business of the non-U.S. shareholder. A non-U.S. shareholder would be taxed on such a distribution at the normal capital gain rates applicable to U.S. shareholders, subject to applicable alternative minimum tax and a special alternative minimum tax in the case of a nonresident alien individual. A non-U.S. corporate shareholder not entitled to treaty relief or exemption also may be subject to the 30% branch profits tax on such a distribution. CubeSmart must withhold 35% of any distribution that CubeSmart could designate as a capital gain dividend. A non-U.S. shareholder may receive a credit against its tax liability for the amount CubeSmart withholds.

Effective beginning on December 18, 2015, our shares were not, and will not be, treated as a USRPI when held, directly or indirectly, by a qualified shareholder and, therefore, FIRPTA is inapplicable to such shares. However, certain investors in a qualified shareholder that owns

more than 10% of our shares (directly or indirectly) that are not themselves qualified shareholders may be subject to FIRPTA withholding. A "qualified shareholder" is a foreign entity that (1)(i) is eligible for the benefits of a comprehensive income tax treaty with the United States that includes an exchange of information program and the principal class of interests of which is listed and regularly traded on one or more recognized stock exchanges (as defined in such comprehensive income tax treaty), or (ii) is a foreign partnership that is created or organized under foreign law as a limited partnership in a jurisdiction that has an agreement for the exchange of information with respect to taxes with the United States and has a class of limited partnership units which is regularly traded on the New York Stock Exchange or Nasdaq Stock Market and the value of such class of limited partnership units is greater than 50% of the value of all of the partnership units of the foreign partnership, (2) is a qualified collective investment vehicle, and (3) maintains records on the identity of each person who, at any time during the foreign person's taxable year, holds directly 5% or more of the class of interests described in (1)(i) or (ii). A "qualified collective investment vehicle" is a foreign person that (x) under the comprehensive income tax treaty described in (1)(i) or (ii) would be eligible for a reduced rate of withholding with respect to dividends paid by a REIT even if such person owned more than 10% of the REIT, (y) is a publicly traded partnership that is a withholding foreign partnership, and would be treated as a United States real property holding corporation if it were a United States corporation, or (z) which is designated as a qualified collective investment vehicle by the Secretary of the Treasury and is either (1) fiscally transparent or (2) required to include dividends in its gross income, but is entitled to a deduction for distributions to its equity investors. Additionally, effective beginning on December 18, 2015, qualified foreign pension funds were not, and will not be, subject to FIRPTA withholding. The rules concerning qualified shareholders and qualified foreign pension funds are complex and investors who believe they may be qualified shareholders or qualified foreign pension funds should consult with their own tax advisors to find out if these rules are applicable to them.

However, distributions attributable to gain from sales or exchanges by CubeSmart of USRPIs are treated as ordinary dividends (not subject to the 35% withholding tax under FIRPTA) if the distribution is made to a non-U.S. shareholder with respect to any class of shares which is "regularly traded" on an established securities market located in the United States and if the non-U.S. shareholder did not own more than 5% of such class of shares at any time during the taxable year. Such distributions will generally be subject to a 30% U.S. withholding tax (subject to reduction under applicable treaty) but a non-U.S. shareholder will not be required to report the distribution on a U.S. tax return. In addition, the branch profits tax will not apply to such distributions.

Taxation of Disposition of Shares. A non-U.S. shareholder generally will not incur tax under FIRPTA with respect to gain on a sale of common shares or preferred shares as long as CubeSmart is a "domestically-controlled REIT," which means that at all times non-U.S. persons hold, directly or indirectly, less than 50% in value of all outstanding CubeSmart shares.

CubeSmart cannot assure you that this test will be met. Further, even if CubeSmart is a domestically controlled REIT, pursuant to "wash sale" rules under FIRPTA, a non-U.S. shareholder may incur tax under FIRPTA. The "wash sale" rule applies to the extent such non-U.S. shareholder disposes of CubeSmart shares during the 30-day period preceding a dividend payment, and such non-U.S. shareholder (or a person related to such non-U.S. shareholder) acquires or enters into a contract or option to acquire CubeSmart common shares or preferred shares within 61 days of the 1st day of the 30 day period described above, and any portion of such dividend payment would, but for the disposition, be treated as a USRPI capital gain to such non-U.S. shareholder, then such non-U.S. shareholder shall be treated as having USRPI capital gain in an amount that, but for the disposition, would have been treated as USRPI capital gain.

In addition, a non-U.S. shareholder that owns, actually or constructively, 10% or less of the outstanding common shares or preferred shares at all times during a specified testing period will not incur tax under FIRPTA on gain from a sale of such common shares or preferred shares if such shares

are "regularly traded" on an established securities market. Because CubeSmart's common shares and preferred shares are "regularly traded" on an established securities market, CubeSmart expects that a non-U.S. shareholder generally will not incur tax under FIRPTA on gain from a sale of common shares or preferred shares unless it owns or has owned more than 10% of such common shares or preferred shares at any time during the five year period to such sale. Any gain subject to tax under FIRPTA will be treated in the same manner as it would be in the hands of U.S. shareholders, subject to alternative minimum tax, but under a special alternative minimum tax in the case of nonresident alien individuals, and the purchaser of the shares could be required to withhold 10% of the purchase price and remit such amount to the IRS.

A non-U.S. shareholder generally will incur tax on gain not subject to FIRPTA if:

Redemptions of Our Preferred Shares. Whenever we redeem any preferred shares, the treatment accorded to any redemption by us for cash (as distinguished from a sale, exchange or other disposition) of our preferred shares to a non-U.S. shareholder of such preferred shares can only be determined on the basis of the particular facts as to each holder at the time of redemption. In general, a non-U.S. shareholder of our preferred shares will recognize capital gain or loss measured by the difference between the amount received by the holder of such shares upon the redemption and such holder's adjusted tax basis in the preferred shares redeemed (provided the preferred shares are held as a capital asset) if such redemption (i) is "substantially disproportionate" with respect to the holder's interest in all classes of our shares under Section 302 (b)(2) of the Code, (ii) results in a "complete termination" of the holder's interest in all classes of our shares under Section 302(b)(3) of the Code, or (iii) is "not essentially equivalent to a dividend" with respect to the holder of the preferred shares under Section 302(b)(1) of the Code. In applying these tests, there must be taken into account not only the preferred shares being redeemed, but also such holder's ownership of other classes and series of our shares and any options (including stock purchase rights) to acquire any of the foregoing. The non-U.S. shareholder of our preferred shares also must take into account any such securities (including options) which are considered to be owned by such holder by reason of the constructive ownership rules set forth in Sections 318 and 302(c) of the Code.

If the non-U.S. shareholder of preferred shares owns (actually or constructively) none of our voting shares, or owns an insubstantial amount of our voting shares, based upon current law, it is probable that the redemption of preferred shares from such a holder would be considered to be "not essentially equivalent to a dividend." However, whether a distribution is "not essentially equivalent to a dividend" depends on all of the facts and circumstances, and a non-U.S. shareholder of our preferred shares intending to rely on any of the tests in this or the preceding paragraph at the time of redemption should consult its tax advisor to determine their application to its particular situation. If the redemption does not meet any of the tests under Section 302 of the Code, then the redemption proceeds received from our preferred shares will be treated as a distribution on our shares as described under "Taxation of Shareholders—Taxation of Non-U.S. Shareholders—Taxation of Distributions."

If the redemption of a holder's preferred shares is taxed as a dividend, the adjusted basis of such holder's redeemed preferred shares will be transferred to any other shares held by the holder. If the holder owns no other shares, under certain circumstances, such basis may be transferred to a related person, or it may be lost entirely.

Conversion of Our Preferred Shares into Common Shares. Except as provided below, a non-U.S. shareholder generally will not recognize gain or loss upon the conversion of our preferred shares into our common shares, provided our preferred shares do not constitute a USRPI. Even if our preferred shares do constitute a USRPI, provided our common shares also constitute a USRPI, a non-U.S. shareholder generally will not recognize gain or loss upon a conversion of our preferred shares into our common shares provided certain reporting requirements are satisfied. Except as provided below, a non-U.S. shareholder's basis and holding period in the common shares received upon conversion will be the same as those of the converted preferred shares (but the basis will be reduced by the portion of adjusted tax basis allocated to any fractional common share exchanged for cash). Any common shares received in a conversion that are attributable to accumulated and unpaid dividends on the converted preferred shares will be treated as a distribution on our shares as described under "—Taxation of Shareholders—Taxation of Non-U.S. Shareholders—Taxation of Distributions." Cash received upon conversion in lieu of a fractional common share generally will be treated as a payment in a taxable exchange for such fractional common share as described under "—Taxation of Shareholders—Taxation of Non-U.S. Shareholders—Taxation of Disposition of Shares." Non-U.S. shareholders should consult with their tax advisors regarding the U.S. federal income tax consequences of any transaction by which such holder exchanges common shares received on a conversion of preferred shares for cash or other property.

Information Reporting and Backup Withholding Applicable to non-U.S. Shareholders

CubeSmart must report annually to the IRS and to each non-U.S. shareholder the amount of dividends paid to such holder and the tax withheld with respect to such dividends, regardless of whether withholding was required. Copies of the information returns reporting such dividends and withholding may also be made available to the tax authorities in the country in which the non-U.S. shareholder resides under the provisions of an applicable income tax treaty.

Payments of dividends or of proceeds from the disposition of shares made to a non-U.S. shareholder may be subject to information reporting and backup withholding unless such holder establishes an exemption, for example, by properly certifying its non-United States status on a properly completed IRS Form W-8 BEN or W-8BEN-E or another appropriate version of IRS Form W-8. Notwithstanding the foregoing, backup withholding may apply if either CubeSmart or its paying agent has actual knowledge, or reason to know, that a non-U.S. shareholder is a United States person.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against the shareholder's income tax liability, provided the required information is timely furnished to the IRS.

Under Sections 1471 through 1474 of the Code (such Sections commonly referred to as "FATCA"), payments of dividends to a non-U.S. shareholder will be subject to 30% withholding tax if the non-U.S. shareholder fails to provide the withholding agent with documentation sufficient to show that it is compliant with the FATCA or otherwise exempt from withholding under FATCA. Generally, such documentation is provided on an executed IRS Form W-8BEN or IRS Form W-8BEN-E, as applicable. If a dividend payment is both subject to withholding under FATCA and subject to withholding tax discussed above, the withholding under FATCA may be credited against, and therefore reduce, such other withholding tax. Starting in 2019, the gross proceeds from certain capital gain dividends or the disposition of our common stock may also be subject to FATCA withholding absent proof of FATCA compliance prior to January 1, 2019. Non-U.S. shareholders should consult their tax advisors to determine the applicability of this legislation in light of their individual circumstances.

The rules dealing with U.S. federal income taxation are constantly under review by persons involved in the legislative process and by the IRS and the U.S. Treasury Department. No assurance can be given as to whether, when, or in what form, the U.S. federal income tax laws applicable to CubeSmart and its shareholders may be enacted. Changes to the federal tax laws and interpretations of U.S. federal tax laws could adversely affect an investment in CubeSmart shares.

This section describes the material U.S. federal income tax consequences of owning the debt securities that the Operating Partnership may offer. This summary is for general information only and is not tax advice. The tax consequences of owning any particular issue of debt securities will be discussed in the applicable prospectus.

As used herein, a "U.S. Holder" means a beneficial owner of debt securities of the Operating Partnership, who is, for U.S. federal income tax purposes:

If a partnership holds debt securities, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. If you are a partner of a partnership holding debt securities of the Operating Partnership, you should consult your tax advisor regarding the consequences of the ownership and disposition of debt securities by the partnership.

Interest. The stated interest on debt securities generally will be taxable to a U.S. Holder as ordinary income at the time that it is paid or accrued, in accordance with the U.S. Holder's method of accounting for U.S. federal income tax purposes.

Original Issue Discount. If you own debt securities issued with original issue discount, or OID, you will be subject to special tax accounting rules, as described in greater detail below. In that case, you should be aware that you generally must include OID in gross income in advance of the receipt of cash attributable to that income. However, you generally will not be required to include separately in income cash payments received on the debt securities, even if denominated as interest, to the extent those payments do not constitute "qualified stated interest," as defined below. If we determine that a particular debt security will be an OID debt security, we will disclose that determination in the prospectus relating to those debt securities.

A debt security with an "issue price" that is less than the "stated redemption price at maturity" (the sum of all payments to be made on the debt security other than "qualified stated interest") generally will be issued with OID if that difference is at least 0.25% of the stated redemption price at maturity multiplied by the number of complete years to maturity. The "issue price" of each debt security in a particular offering will be the first price at which a substantial amount of that particular offering is sold to the public. The term "qualified stated interest" means stated interest that is unconditionally payable in cash or in property, other than debt instruments of the issuer, and the interest to be paid meets all of the following conditions:

If we determine that particular debt securities of a series will bear interest that is not qualified stated interest, we will disclose that determination in the prospectus relating to those debt securities.

If you own a debt security issued with "de minimis" OID, which is discount that is not OID because it is less than 0.25% of the stated redemption price at maturity multiplied by the number of complete years to maturity, you generally must include the de minimis OID in income at the time principal payments on the debt securities are made in proportion to the amount paid. Any amount of de minimis OID that you have included in income will be treated as capital gain.

Certain of the debt securities may contain provisions permitting them to be redeemed prior to their stated maturity at our option and/or at your option. OID debt securities containing those features may be subject to rules that differ from the general rules discussed herein. If you are considering the purchase of OID debt securities with those features, you should carefully examine the applicable prospectus and should consult your own tax advisor with respect to those features since the tax consequences to you with respect to OID will depend, in part, on the particular terms and features of the debt securities.

If you own OID debt securities with a maturity upon issuance of more than one year you generally must include OID in income in advance of the receipt of some or all of the related cash payments using the "constant yield method" described in the following paragraphs. This method takes into account the compounding of interest.

The amount of OID that you must include in income if you are the initial United States holder of an OID debt security is the sum of the "daily portions" of OID with respect to the debt security for each day during the taxable year or portion of the taxable year in which you held that debt security, or accrued OID. The daily portion is determined by allocating to each day in any "accrual period" a pro rata portion of the OID allocable to that accrual period. The "accrual period" for an OID debt security may be of any length and may vary in length over the term of the debt security, provided that each accrual period is no longer than one year and each scheduled payment of principal or interest occurs

on the first day or the final day of an accrual period. The amount of OID allocable to any accrual period is an amount equal to the excess, if any, of:

OID allocable to a final accrual period is the difference between the amount payable at maturity, other than a payment of qualified stated interest, and the adjusted issue price at the beginning of the final accrual period. Special rules will apply for calculating OID for an initial short accrual period. The "adjusted issue price" of a debt security at the beginning of any accrual period is equal to its issue price increased by the accrued OID for each prior accrual period, determined without regard to the amortization of any acquisition or bond premium, as described below, and reduced by any payments made on the debt security (other than qualified stated interest) on or before the first day of the accrual period. Under these rules, you will generally have to include in income increasingly greater amounts of OID in successive accrual periods. We are required to provide information returns stating the amount of OID accrued on debt securities held of record by persons other than corporations and other exempt holders.

Floating rate debt securities are subject to special OID rules. In the case of an OID debt security that is a floating rate debt security, both the "yield to maturity" and "qualified stated interest" will be determined solely for purposes of calculating the accrual of OID as though the debt security will bear interest in all periods at a fixed rate generally equal to the rate that would be applicable to interest payments on the debt security on its date of issue or, in the case of certain floating rate debt securities, the rate that reflects the yield to maturity that is reasonably expected for the debt security. Additional rules may apply if either:

This discussion does not address the tax rules applicable to debt securities with an indexed principal amount. If you are considering the purchase of floating rate OID debt securities or securities with indexed principal amounts, you should carefully examine the prospectus relating to those debt securities, and should consult your own tax advisor regarding the U.S. federal income tax consequences to you of holding and disposing of those debt securities.

You may elect to treat all interest on any debt securities as OID and calculate the amount includible in gross income under the constant yield method described above. For purposes of this election, interest includes stated interest, acquisition discount, OID, de minimis OID, market discount, de minimis market discount and unstated interest, as adjusted by any amortizable bond premium or acquisition premium. You must make this election for the taxable year in which you acquired the debt security, and you may not revoke the election without the consent of the IRS. You should consult with your own tax advisor about this election.

Market Discount. If you purchase debt securities, other than OID debt securities, after original issuance for an amount that is less than their stated redemption price at maturity, or, in the case of OID debt securities, their adjusted issue price, the amount of the difference will be treated as "market discount" for U.S. federal income tax purposes, unless that difference is less than a specified de minimis amount. Under the market discount rules, you will be required to treat any principal payment on, or any gain on the sale, exchange, retirement or other disposition of, the debt securities as ordinary income to the extent of the market discount that you have not previously included in income and are treated as having accrued on the debt securities at the time of their payment or disposition. In

addition, you may be required to defer, until the maturity of the debt securities or their earlier disposition in a taxable transaction, the deduction of all or a portion of the interest expense on any indebtedness attributable to the debt securities. You may elect, on a debt security-by-debt security basis, to deduct the deferred interest expense in a tax year prior to the year of disposition. You should consult your own tax advisor before making this election.

Any market discount will be considered to accrue ratably during the period from the date of acquisition to the maturity date of the debt securities, unless you elect to accrue on a constant interest method. You may elect to include market discount in income currently as it accrues, on either a ratable or constant interest method, in which case the rule described above regarding deferral of interest deductions will not apply. Your election to include market discount in income currently, once made, applies to all market discount obligations acquired by you on or after the first taxable year to which your election applies and may not be revoked without the consent of the IRS. You should consult your own tax advisor before making this election.

Acquisition Premium and Amortizable Bond Premium. If you purchase OID debt securities for an amount that is greater than their adjusted issue price but equal to or less than the sum of all amounts payable on the debt securities after the purchase date other than payments of qualified stated interest, you will be considered to have purchased those debt securities at an "acquisition premium." Under the acquisition premium rules, the amount of OID that you must include in gross income with respect to those debt securities for any taxable year will be reduced by the portion of the acquisition premium properly allocable to that year.

If you purchase debt securities (including OID debt securities) for an amount in excess of the sum of all amounts payable on those debt securities after the purchase date other than qualified stated interest, you will be considered to have purchased those debt securities at a "premium" and, if they are OID debt securities, you will not be required to include any OID in income. You generally may elect to amortize the premium over the remaining term of those debt securities on a constant yield method as an offset to interest when includible in income under your regular accounting method.

In the case of debt securities that provide for alternative payment schedules, bond premium is calculated by assuming that (a) you will exercise or not exercise options in a manner that maximizes your yield, and (b) we will exercise or not exercise options in a manner that minimizes your yield (except that we will be assumed to exercise call options in a manner that maximizes your yield). If you do not elect to amortize bond premium, that premium will decrease the gain or increase the loss you would otherwise recognize on disposition of the debt security. Your election to amortize premium on a constant yield method will also apply to all debt obligations held or subsequently acquired by you on or after the first day of the first taxable year to which the election applies. You may not revoke the election without the consent of the IRS. You should consult your own tax advisor before making this election.

Sale, Exchange and Retirement of Debt Securities. A U.S. Holder of debt securities will recognize gain or loss upon the sale, exchange, retirement, redemption or other taxable disposition of such debt securities in an amount equal to the difference between:

A U.S. Holder's adjusted tax basis in a debt security generally will equal the cost of the debt security to such holder (A) increased by the amount of OID or accrued market discount (if any) previously included in income by such holder and (B) decreased by the amount of (1) any payments

other than qualified stated interest payments and (2) any amortizable bond premium taken by the holder.

Any gain or loss recognized will generally be capital gain or loss, and such capital gain or loss will generally be long-term capital gain or loss if the debt security has been held by the U.S. Holder for more than one year. Long-term capital gain for non-corporate taxpayers is subject to reduced rates of U.S. federal income taxation (currently, a 20% maximum federal rate). The deductibility of capital losses is subject to certain limitations.

If a U.S. Holder recognizes a loss upon a subsequent disposition of debt securities in an amount that exceeds a prescribed threshold, it is possible that the provisions of Treasury regulations involving "reportable transactions" could apply, with a resulting requirement to separately disclose the loss generating transactions to the IRS. While these regulations are directed towards "tax shelters," they are written broadly, and apply to transactions that would not typically be considered tax shelters. Significant penalties apply for failure to comply with these requirements. You should consult your tax advisor concerning any possible disclosure obligation with respect to the receipt or disposition of debt securities, or transactions that might be undertaken directly or indirectly by us. Moreover, you should be aware that we and other participants in transactions involving us (including our advisors) might be subject to disclosure or other requirements pursuant to these regulations.

Certain U.S. Shareholders and U.S. Holders who are individuals, estates or trusts and whose income exceeds certain thresholds may be required to pay a 3.8% Medicare tax on "net investment income" which includes, among other things, dividends on shares, interest on debentures and capital gains from the sale or other disposition of shares or debentures, subject to certain exceptions. Prospective investors should consult their tax advisors regarding the effect, if any, of this legislation on their ownership and disposition of our common shares, preferred shares or debentures.

Assuming the debt security is debt for tax purposes, interest income accrued on the debt security should not constitute unrelated business taxable income to a tax-exempt holder. As a result, a tax-exempt holder generally should not be subject to U.S. federal income tax on the interest income accruing on debt securities of the Operating Partnership. Similarly, any gain recognized by the tax-exempt holder in connection with a sale of the debt security generally should not be unrelated business taxable income. However, if a tax-exempt holder were to finance its acquisition of the debt security with debt, a portion of the interest income and gain attributable to the debt security would constitute unrelated business taxable income pursuant to the "debt-financed property" rules. Tax-exempt holders should consult their own counsel to determine the potential tax consequences of an investment in debt securities of the Operating Partnership.

The term "non-U.S. Holder" means a beneficial owner of debt securities of the Operating Partnership that is not a U.S. Holder or a partnership (or an entity treated as a partnership for U.S. federal income tax purposes). The rules governing U.S. federal income taxation of non-U.S. Holders are complex. This section is only a summary of such rules. We urge non-U.S. Holders to consult their own tax advisors to determine the impact of federal, state, local and foreign income tax laws on ownership of debt securities, including any reporting requirements.

Interest. Interest (including OID) paid to a non-U.S. Holder of debt securities will not be subject to U.S. federal income or withholding tax under the "portfolio interest exemption," provided that:

A payment of interest (including OID) to a non-U.S. Holder that does not qualify for the portfolio interest exemption and that is not effectively connected to a United States trade or business will be subject to United States federal withholding tax at a rate of 30%, unless a United States income tax treaty applies to reduce or eliminate withholding.

A non-U.S. Holder will generally be subject to tax in the same manner as a U.S. Holder with respect to payments of interest (including OID) if such payments are effectively connected with the conduct of a trade or business by the non-U.S. Holder in the United States and, if an applicable tax treaty provides, such gain is attributable to a United States permanent establishment maintained by the non-U.S. Holder. In some circumstances, such effectively connected income received by a non-U.S. Holder which is a corporation may be subject to an additional "branch profits tax" at a 30% base rate or, if applicable, a lower treaty rate.

To claim the benefit of a lower treaty rate or to claim exemption from withholding because the income is effectively connected with a United States trade or business, the non-U.S. Holder must provide a properly executed IRS Form W-8BEN or W-8BEN-E or IRS Form W-8ECI or other applicable form, or a suitable substitute form, as applicable, prior to the payment of interest. Such certificate must contain, among other information, the name and address of the non-U.S. Holder.

Non-U.S. Holders are urged to consult their own tax advisors regarding applicable income tax treaties, which may provide different rules.

Sale or Retirement of Debt Securities. A non-U.S. Holder generally will not be subject to U.S. federal income tax or withholding tax on gain realized on the sale, exchange or redemption of debt securities unless:

Except to the extent that an applicable tax treaty provides otherwise, a non-U.S. Holder will generally be subject to tax in the same manner as a U.S. Holder with respect to gain realized on the sale, exchange or redemption of debt securities if such gain is effectively connected with the conduct of

a trade or business by the non-U.S. Holder in the United States and, if an applicable tax treaty provides, such gain is attributable to a United States permanent establishment maintained by the non-U.S. Holder. In certain circumstances, a non-U.S. Holder that is a corporation will be subject to an additional "branch profits tax" at a 30% rate or, if applicable, a lower treaty rate on such income.

U.S. Federal Estate Tax. Your estate will not be subject to U.S. federal estate tax on the debt securities beneficially owned by you at the time of your death, provided that any payment to you on the debt securities, including OID, would be eligible for exemption from the 30% U.S. federal withholding tax under the "portfolio interest exemption" described above, without regard to the certification requirement.

Information Reporting and Backup Withholding Applicable to Holders of Debt Securities

Certain U.S. Holders may be subject to information reporting requirements on payments of principal and interest (including OID) on debt securities and payments of the proceeds of the sale, exchange, or redemption of debt securities, and backup withholding, currently imposed at a rate of 28%, may apply to such payment if the U.S. Holder:

A non-U.S. Holder is generally not subject to backup withholding with respect to payments of interest (including OID) on debt securities if it certifies as to its status as a non-U.S. Holder under penalties of perjury or if it otherwise establishes an exemption, provided that neither we nor our paying agent has actual knowledge or reason to know that the non-U.S. Holder is a United States person or that the conditions of any other exemptions are not, in fact, satisfied. Information reporting requirements, however, will apply to payments of interest (including OID) to non-U.S. Holders where such interest is subject to withholding or exempt from United States withholding tax pursuant to a tax treaty. Copies of these information returns may also be made available under the provisions of a specific treaty or agreement to the tax authorities of the country in which the non-U.S. Holder resides.

The payment of the proceeds from the disposition of debt securities to or through the United States office of any broker, United States or foreign, will be subject to information reporting and possible backup withholding unless the owner certifies as to its non-United States status under penalties of perjury or otherwise establishes an exemption, provided that the broker does not have actual knowledge or reason to know that the non-U.S. Holder is a United States person or that the conditions of any other exemption are not, in fact, satisfied.

The payment of the proceeds from the disposition of debt securities to or through a non-United States office of a non-United States broker that is not a "United States related person" generally will not be subject to information reporting or backup withholding. For this purpose, a "United States related person" is:

In the case of the payment of proceeds from the disposition of debt securities to or through a non-United States office of a broker that is either a United States person or a United States related person, the payment may be subject to information reporting unless the broker has documentary evidence in its files that the owner is a non-U.S. Holder and the broker has no knowledge or reason to know to the contrary. Backup withholding will not apply to payments made through foreign offices of a broker that is a United States person or a United States related person, absent actual knowledge that the payee is a United States person.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules from a payment to a Holder will be allowed as a refund or a credit against such Holder's U.S. federal income tax liability, provided that the requisite procedures are followed.

Holders of debt securities are urged to consult their tax advisors regarding their qualification for exemption from backup withholding and the procedure for obtaining such an exemption, if applicable.

Payments of interest to a non-U.S. holder will be subject to a 30% withholding tax if the non-U.S. holder fails to provide the withholding agent with documentation sufficient to show that it is compliant FATCA. Generally such documentation is provided on an executed IRS Form W-8BEN or IRS Form W-8BEN-E, as applicable. If interest is subject to the 30% tax under FATCA, it will not be subject to the 30% tax described above under "Taxation of Non-U.S. Shareholders" and "Taxation of Non-U.S. Holders of Debt Securities." Starting in 2019, payments of the gross proceeds may also be subject to FATCA withholding absent proof of FATCA compliance prior to January 1, 2019. Prospective investors should consult their tax advisors regarding the possible implications of this legislation on their investment in common shares or preferred shares of CubeSmart or debt securities of the Operating Partnership.

We and, where applicable, selling securityholders, may sell the securities from time to time in one or more transactions, including block transactions and transactions on the NYSE or on a delayed or continuous basis, in each case, through:

The securities may be sold at a fixed price or prices, which may be changed, or at market prices prevailing at the time of sale, at prices relating to the prevailing market prices or at negotiated prices. The consideration may be cash or another form negotiated by the parties. Agents, underwriters or broker-dealers may be paid compensation for offering and selling the securities. That compensation may be in the form of discounts, concessions or commissions to be received from us or from the purchasers of the securities.

For each offering of common shares, preferred shares, depositary shares, subscriptions rights, warrants or debt securities, the prospectus supplement or other offering materials will describe the specific plan, including:

If we use underwriters for a sale of securities, the underwriters may offer and sell the securities at a fixed price or prices, which may be changed, or from time to time at market prices prevailing at the time of sale, at prices related to such prevailing market prices, at negotiated prices or under delayed delivery contracts or other contractual commitments. We also may, from time to time, authorize underwriters acting as agents to offer and sell the securities upon the terms and conditions set forth in any prospectus supplement. Underwriters may sell the securities to or through dealers, and such dealers may receive compensation in the form of discounts, concessions or commissions (which may be changed from time to time) from the underwriters and/or from the purchasers for whom they may act as agent.

Offers to purchase the securities may be solicited by agents designated by us from time to time. Any such agent involved in the offer or sale of the securities will be named, and any commissions payable by the Company to such agent will be set forth in the prospectus supplement. Unless otherwise indicated in the prospectus supplement, any such agent will be acting on a best efforts basis for the

period of its appointment. Any such agent may be deemed to be an underwriter, as that term is defined in the Securities Act, of the securities so offered and sold.

We may from time to time engage a firm to act as our agent for one or more offerings of our securities. We sometimes refer to this agent as our "offering agent." If we reach agreement with an offering agent with respect to a specific offering, including the number of securities and any minimum price below which sales may not be made, then the offering agent will try to sell such securities on the agreed terms. The offering agent could make sales in privately negotiated transactions and/or any other method permitted by law, including sales deemed to be an "at-the-market" offering as defined in Rule 415 promulgated under the Securities Act, including sales made directly on the NYSE, or sales made to or through a market maker other than on an exchange. The offering agent will be deemed to be an "underwriter" within the meaning of the Securities Act with respect to any sales effected through an "at-the-market" offering.

If an underwriter or underwriters are utilized in the sale of securities, we will execute an underwriting agreement with such underwriter or underwriters at the time an agreement for such sale is reached, and the names of the specific managing underwriter or underwriters, as well as any other underwriters, and the terms of the transactions, including compensation of the underwriters and dealers, if any, will be set forth in the prospectus supplement, which will be used by the underwriters to resell the securities.

If a dealer is utilized in the sale of the securities, we will sell such securities to the dealer, as principal. The dealer may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale. The name of the dealer and the terms of the transactions will be set forth in the prospectus supplement relating thereto.

Offers to purchase the securities may be solicited directly by us and sales thereof may be made by us directly to institutional investors or others. The terms of any such sales, including the terms of any bidding or auction prices, if utilized, will be described in the prospectus supplement relating thereto.

Some or all of the securities that we offer through this prospectus may be new issues of securities with no established trading market. Any underwriters to whom we sell securities for public offering and sale may make a market in those securities, but they will not be obligated to and they may discontinue any market making at any time without notice. Accordingly, we cannot assure you of the liquidity of, or continued trading markets for, any securities offered pursuant to this prospectus. If we use dealers in the sale, we will sell securities to those dealers as principals. The dealers may then resell the securities to the public at any market price or other prices to be determined by the dealers at the time of resale. If we use agents in the sale, unless we inform you otherwise in the prospectus supplement or other applicable offering materials, they will use their reasonable best efforts to solicit purchasers for the period of their appointment. If we sell directly, no underwriters or agents would be involved. In the prospectus supplement or other applicable offering materials, we will name any agent involved in the offer or sale of the offered securities, and we will describe any commissions payable to the agent. We are not making an offer of securities in any state that does not permit such an offer.

If indicated in the applicable prospectus supplement, we may authorize underwriters or other persons acting as our agents to solicit offers by institutions or other suitable purchasers to purchase the securities from us at the public offering price set forth in the prospectus supplement, pursuant to delayed delivery contracts providing for payment and delivery on the date or dates stated in the prospectus supplement. These purchasers may include, among others, commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but will in all cases be subject to our approval. Delayed delivery contracts will be subject to the condition that the purchase of the securities covered by the delayed delivery contracts will not at the time of delivery be prohibited under the laws of any jurisdiction in the United States to

which the purchaser is subject. The underwriters and agents will not have any responsibility with respect to the validity or performance of these contracts.

To facilitate the offering of the securities, certain persons participating in the offering may engage in transactions that stabilize, maintain, or otherwise affect the price of the securities. This may include over-allotments or short sales of the securities, which involves the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover the over-allotments or short positions by making purchases in the open market or by exercising their over-allotment option. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing securities in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and any discounts and commissions received by them from us or from purchasers of the securities and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions under the Securities Act. If such dealers or agents were deemed to be underwriters, they may be subject to statutory liabilities under the Securities Act. Underwriters, dealers and agents may be entitled, under agreements entered into with us, to indemnification against and contribution toward certain civil liabilities, including liabilities under the Securities Act.

In the ordinary course of business, we may engage in transactions with underwriters, dealers, agents and their affiliates and they may perform services for us.

Unless otherwise set forth in a prospectus supplement, the validity of the securities offered and certain tax matters will be passed upon for us by Pepper Hamilton LLP.

The consolidated financial statements and financial statement schedules of CubeSmart and CubeSmart, L.P. as of December 31, 2016 and 2015 and for each of the years in the three-year period ended December 31, 2016 and management's assessment of the effectiveness of internal control over financial reporting as of December 31, 2016 have been incorporated by reference herein in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing. The audit report covering the December 31, 2016 financial statements dated February 17, 2017 refers to a change in the method of reporting discontinued operations in 2014.

CUBESMART, L.P.
% Senior Notes due
Fully and Unconditionally Guaranteed by CubeSmart

	Per Note	Total




Public offering price(1)	$	$

Underwriting discount	$	$

Proceeds, before expenses, to CubeSmart, L.P.(1)	$	$


PROSPECTUS SUPPLEMENT
About This Prospectus Supplement		S-1
Forward-Looking Statements		S-1
Summary		S-4
The Offering		S-5
Risk Factors		S-8
Use of Proceeds		S-11
Capitalization		S-12
Description of the Notes and the Guarantee		S-13
Material United States Federal Income Tax Considerations		S-23
Underwriting (Conflicts of Interest)		S-30
Legal Matters		S-36
Experts		S-36
Incorporation of Certain Information by Reference		S-37
Where You Can Find More Information		S-38


TABLE OF CONTENTS
ABOUT THIS PROSPECTUS			1
WHERE YOU CAN FIND MORE INFORMATION			1
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE			2
FORWARD-LOOKING STATEMENTS			2
CUBESMART AND THE OPERATING PARTNERSHIP			4
RISK FACTORS			4
USE OF PROCEEDS			4
RATIO OF EARNINGS TO FIXED CHARGES AND RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERENCE DIVIDENDS			5
DESCRIPTION OF CUBESMART'S CAPITAL SHARES			6
DESCRIPTION OF DEPOSITARY SHARES			12
DESCRIPTION OF SUBSCRIPTION RIGHTS			15
DESCRIPTION OF WARRANTS			16
DESCRIPTION OF THE DEBT SECURITIES			17
SELLING SECURITYHOLDERS			32
MATERIAL FEDERAL INCOME TAX CONSIDERATIONS			32
PLAN OF DISTRIBUTION			67
LEGAL MATTERS			69
EXPERTS			69

	For the years ended December 31,

	2016		2015		2014		2013		2012
Ratio of earnings to fixed charges(a)		2.45		2.56		1.50		1.22		0.70

	For the years ended December 31,

	2016		2015		2014		2013		2012
Ratio of earnings to combined fixed charges and preference dividends(a)(b)		2.26		2.28		1.34		1.07		0.61


PROSPECTUS
About this Prospectus			1
Where You Can Find More Information			1
Incorporation of Certain Information by Reference			2
Forward-Looking Statements			2
CubeSmart And The Operating Partnership			4
Risk Factors			4
Use of Proceeds			4
Ratio of Earnings to Fixed Charges and Ratio of Earnings to Combined Fixed Charges and Preference Dividends			5
Description of CubeSmart's Capital Shares			6
Description of Depositary Shares			12
Description of Subscription Rights			15
Description of Warrants			16
Description of The Debt Securities			17
Material Federal Income Tax Considerations			32
Plan of Distribution			67
Legal Matters			69
Experts			69

Underwriter		Principal Amount of Notes

Wells Fargo Securities, LLC
Barclays Capital Inc.
Jefferies LLC

Total		$


Wells Fargo Securities		Barclays		Jefferies


Wells Fargo Securities		Barclays		Jefferies

Section 1: 424B5 (424B5)