SmartStop Self Storage REIT, Inc.

FOR THE YEAR ENDED DECEMBER 31, 2025

REPORT OF INDEPENDENT REGIST ERED PUBLIC ACCOUNTING FIRM

Shareholders and Board of Directors

Ladera Ranch, California

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of SmartStop Self Storage REIT, Inc. (the “Company”) as of December 31, 2025 and 2024, the related consolidated statements of operations, comprehensive income (loss), equity and temporary equity, and cash flows for each of the three years in the period ended December 31, 2025, and the related notes and financial statement schedule listed in the accompanying index (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (“PCAOB”), the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) and our report dated February 27, 2026 expressed an unqualified opinion thereon.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of the critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing separate opinions on the critical audit matter or on the accounts or disclosures to which it relates.

Real Estate Purchase Price Allocations

As described in Note 3 of the Company’s consolidated financial statements, the Company completed the acquisition of 17 self-storage properties for approximately $332.2 million during the year ended December 31, 2025. As described in Note 2 of the consolidated financial statements, the Company allocates the purchase price of an asset acquisition to the tangible and intangible assets acquired and the liabilities assumed based on their relative fair values as of the acquisition date. The fair values of these assets and liabilities were determined as of the acquisition dates using multiple valuation techniques.

We identified the estimation of the fair values of the land and buildings used in the real estate purchase price allocations as a critical audit matter because of the level of judgment required to estimate the fair values of the acquired land and buildings that utilize multiple valuation techniques. Auditing the fair value measurements involved especially subjective auditor judgments due to the nature and extent of audit effort required, including the use of personnel with specialized knowledge and skills.

The primary procedures we performed to address this critical audit matter included:

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Reading the purchase and sale agreements and other closing documents to understand the terms of the transactions.

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Testing the completeness and accuracy of certain property data supporting certain assumptions and estimates utilized in the valuation models by comparing to source documents.

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Utilizing personnel with specialized knowledge and skills in valuation to assess the valuation methods used by the Company.

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To test the fair value of the buildings, comparing significant assumptions used in the income approach to market data and, for certain of the comparisons, utilizing personnel with specialized knowledge and skills in valuation to compare assumptions used to market data.

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To test the fair value of land, utilizing personnel with specialized knowledge and skills in valuation by assessing the appropriateness of management’s selected comparable land sales utilized in the market approach by evaluating market data.

/s/BDO USA, P.C.

We have served as the Company’s auditor since 2017.

Costa Mesa, California

February 27, 2026