IRON MOUNTAIN INC

(a)Financial Statements filed as part of this report:

(b)Exhibits filed as part of this report: As listed in the Exhibit Index following the Financial Statement Schedule III-Schedule of Real Estate and Accumulated Depreciation.

Part IV

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the shareholders and the Board of Directors of Iron Mountain Incorporated

OPINION ON THE FINANCIAL STATEMENTS

We have audited the accompanying consolidated balance sheets of Iron Mountain Incorporated and subsidiaries (the "Company") as of December 31, 2025 and 2024, the related consolidated statements of operations, comprehensive income (loss), (deficit) equity, and cash flows, for each of the three years in the period ended December 31, 2025, and the related notes and the schedule listed in the Index at Item 15 (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of 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 have also 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 and our report dated February 12, 2026, expressed an unqualified opinion on the Company's internal control over financial reporting.

BASIS FOR OPINION

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's 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 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 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 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 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 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 financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Part IV

GOODWILL - ASSET LIFECYCLE MANAGEMENT REPORTING UNIT - REFER TO NOTE 2.L. TO THE FINANCIAL STATEMENTS

CRITICAL AUDIT MATTER DESCRIPTION

The Company’s evaluation of goodwill for impairment involves the comparison of the fair value of the reporting unit to its carrying value. The Company determined the fair value of the Asset Lifecycle Management reporting unit based on the present value of future cash flows (the "Discounted Cash Flow Model"). The determination of the fair value using the Discounted Cash Flow Model requires management to make significant assumptions related to future revenue growth rates and discount rates. Changes in economic and operating conditions impacting these assumptions could result in goodwill impairment in future periods. The goodwill balance allocated to the Asset Lifecycle Management reporting unit was $781.1 million as of October 1, 2025 (goodwill impairment measurement date). The fair value of the Asset Lifecycle Management reporting unit exceeded its carrying value as of the measurement date and, therefore, no impairment was recognized.

We identified the evaluation of goodwill for the Asset Lifecycle Management reporting unit for impairment as a critical audit matter because of the significant judgments made by management to estimate the fair value of the Asset Lifecycle Management reporting unit. Performing audit procedures to evaluate the reasonableness of management’s estimates and assumptions related to selection of the discount rate and forecasts of future revenue of the Asset Lifecycle Management reporting unit required a high degree of auditor judgment and an increased extent of effort, including the need to involve our fair value specialists.

HOW THE CRITICAL AUDIT MATTER WAS ADDRESSED IN THE AUDIT

Our audit procedures related to testing the reasonableness of key assumptions within the Discounted Cash Flow Model of the Asset Lifecycle Management reporting unit. The key assumptions include future revenue growth rates and the selection of the discount rate. We performed the following procedures as part of the audit:

•We tested the effectiveness of controls over the evaluation of goodwill for impairment, including those over the Discounted Cash Flow Model and discount rate.

•We evaluated management’s ability to accurately forecast by comparing actual results to management’s historical forecasts.

•We evaluated the reasonableness of the revenue growth rates presented within management’s Discounted Cash Flow Model by comparing it to (1) historical results, (2) internal communications to management and the Board of Directors, and (3) forecasted information included in Company press releases and industry reports in which Asset Lifecycle Management operates.

•With the assistance of our fair value specialists, we evaluated the discount rate, including testing the underlying source information and the mathematical accuracy of the calculation, and developing a range of independent estimates and comparing that to the discount rate selected by management.

/s/Deloitte & Touche LLP

Boston, Massachusetts

February 12, 2026

We have served as the Company’s auditor since 2002.