IRON MOUNTAIN INC

Part IV

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1. NATURE OF BUSINESS

The accompanying financial statements represent the consolidated accounts of Iron Mountain Incorporated, a Delaware corporation ("IMI"), and its subsidiaries ("we" or "us").

IMI was founded in an underground facility near Hudson, New York in 1951 where it stored business records. Today, we are a global leader in information management services, and we are trusted by more than 240,000 customers in 61 countries, including approximately 95% of the Fortune 1000, to help unlock value and intelligence from their assets through services that transcend the physical and digital worlds. Our broad range of solutions address their information management, digital transformation, information security, data center and asset lifecycle management (“ALM”) needs. Our longstanding commitment to safety, security, sustainability and innovation in support of our customers underpins everything we do. We currently serve customers across an array of market verticals — commercial, legal, financial, healthcare, technology, insurance, life sciences, energy, business services, entertainment and government organizations.

We have been organized and have operated as a real estate investment trust for United States federal income tax purposes ("REIT") beginning with our taxable year ended December 31, 2014.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

A. PRINCIPLES OF CONSOLIDATION

The accompanying financial statements reflect our financial position, results of operations, comprehensive income (loss), (deficit) equity and cash flows on a consolidated basis. The accompanying financial statements include the results of those entities over which we have a controlling financial interest or of which we are deemed to be the primary beneficiary. All intercompany transactions and account balances have been eliminated.

B. USE OF ESTIMATES

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires us to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the related disclosure of contingent assets and liabilities at the date of the financial statements and for the period then ended. On an ongoing basis, we evaluate the estimates used. We base our estimates on historical experience, actuarial estimates, current conditions and various other assumptions that we believe to be reasonable under the circumstances. These estimates form the basis for making judgments about the carrying values of assets and liabilities and are not readily apparent from other sources. Actual results may differ from these estimates.

C. CHANGES IN PRESENTATION

Certain items previously reported under specific captions within Note 2.i. and Note 9 have been reclassified to conform to the current year presentation.

D. FOREIGN CURRENCY

Local currencies are the functional currencies for our operations outside the United States, with the exception of certain foreign holding companies, whose functional currency is the United States dollar. In those instances where the local currency is the functional currency, assets and liabilities are translated at period-end exchange rates, and revenues and expenses are translated at average exchange rates for the applicable period. See Note 2.r.

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E. CASH AND CASH EQUIVALENTS

Cash and cash equivalents include cash on hand and cash invested in highly liquid short-term securities, which have remaining maturities at the date of purchase of less than 90 days. Cash and cash equivalents are carried at cost, which approximates fair value.

F. ALLOWANCE FOR DOUBTFUL ACCOUNTS AND CREDIT MEMO RESERVES

We maintain an allowance for doubtful accounts and a credit memo reserve for estimated losses resulting from the potential inability of our customers to make required payments and potential disputes regarding billing and service issues. We evaluate and monitor the collectability of accounts receivable based on a combination of factors, including historical loss experience, assessments of trends in our aged receivables and credit memo activity, the location of our businesses, the composition of our customer base, our product and service lines, potential future macroeconomic factors, including natural disasters, and reasonable and supportable forecasts for expected future collectability of our outstanding receivables. Continued adjustments will be made, as it becomes evident, should there be any material change to reasonable and supportable forecasts that may impact our likelihood of collection. Our highly diverse global customer base, with no single customer accounting for more than approximately 3% of revenue during the years ended December 31, 2025, 2024 and 2023, limits our exposure to concentration of credit risk. Additionally, we write off uncollectible balances as circumstances warrant, generally no later than one year past due.

The rollforward of the allowance for doubtful accounts and credit memo reserves is as follows:

(1)Primarily consists of the issuance of credit memos, the write-off of accounts receivable and the impact associated with currency translation adjustments.

G. CONCENTRATIONS OF CREDIT RISK

Financial instruments that potentially subject us to credit risk consist principally of cash and cash equivalents (including money market funds and time deposits) and accounts receivable. We had no significant concentrations of liquid investments as of December 31, 2025 and 2024. As per our risk management investment policy, we limit exposure to concentration of credit risk by limiting the amount invested in any one mutual fund to a maximum of 1% of the fund's total assets or in any one financial institution to a maximum of $75,000. See Note 2.p.

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H. PREPAID EXPENSES AND ACCRUED EXPENSES

Prepaid expenses totaled $145,257 and $131,615 as of December 31, 2025 and 2024, respectively and taxes receivable totaled $97,289 and $46,523 as of December 31, 2025 and 2024, respectively. There were no other items greater than 5% of Total Current Assets included within Prepaid expenses and other as of December 31, 2025 and 2024.

Accrued expenses and other current liabilities with items greater than 5% of total current liabilities are shown separately and consist of the following:

I. PROPERTY, PLANT AND EQUIPMENT

Property, plant and equipment are stated at cost and depreciated using the straight-line method with the following useful lives (in years):

Property, plant and equipment (including financing leases in the respective categories), at cost, consist of the following:

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Minor maintenance costs are expensed as incurred. Major improvements which (i) extend the life, (ii) increase the capacity or functionality or (iii) improve the safety or the efficiency of property owned are capitalized and depreciated. Major improvements to buildings under operating leases are capitalized as leasehold improvements and depreciated. Major improvements to buildings under financing leases are capitalized as building improvements and depreciated.

CAPITALIZED INTEREST

We capitalize interest expense during the active construction period of major capital projects. Capitalized interest is added to the cost of the underlying assets and is amortized over the useful lives of the assets. During the years ended December 31, 2025, 2024 and 2023, capitalized interest is as follows:

INTERNAL USE SOFTWARE

We develop various software applications for internal use. Computer software costs associated with internal use software are expensed as incurred until certain capitalization criteria are met. Third party consulting costs, as well as payroll and related costs for employees directly associated with, and devoting time to, the development of internal use computer software projects (to the extent time is spent directly on the project) are capitalized. Capitalization of costs, including costs incurred for upgrades and enhancements that provide additional functionality to our existing software, generally begins during the application development stage of the project, which occurs after it is probable that the project will be completed and used to perform the function intended. Capitalization ends when the asset is ready for its intended use. Capitalized internal use software costs are depreciated on a straight-line basis over the expected useful life of the software, commencing when the software is ready for its intended use. Computer software costs that are capitalized are periodically evaluated for impairment.

During the years ended December 31, 2025, 2024 and 2023, capitalized costs associated with the development of internal use computer software projects are as follows:

ASSET RETIREMENT OBLIGATIONS

Entities are required to record the fair value of a liability for an asset retirement obligation in the period in which it is incurred. Asset retirement obligations represent the costs to replace or remove tangible long-lived assets required by law, regulatory rule or contractual agreement. Our asset retirement obligations are primarily the result of requirements under our facility lease agreements which generally have "return to original condition" clauses which would require us to remove or restore items such as shred pits, vaults, demising walls and office build-outs, among others. The significant assumptions used in estimating our aggregate asset retirement obligations are the timing of removals, the probability of a requirement to perform, estimated cost and associated expected inflation rates that are consistent with historical rates and credit-adjusted risk-free rates that approximate our incremental borrowing rate. Our asset retirement obligations at December 31, 2025 and 2024 were $62,972 and $43,844, respectively, and are included in Other Long-term Liabilities in our Consolidated Balance Sheets.

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J. LEASES

We lease facilities for certain warehouses, data centers and office spaces. We also have land leases, including those on which certain facilities are located. The majority of our leased facilities are classified as operating leases that, on average, have initial lease terms offive to 10 years, withone or more lease renewal options to extend the lease term. Our lease renewal option terms generally range fromone tofive years. The exercise of the lease renewal option is generally at our sole discretion and may contain fixed rent, fair market value based rent or Consumer Price Index rent escalation clauses. We include option periods in the lease term when our failure to renew the lease would result in an economic disincentive, thereby making it reasonably certain that we will renew the lease. We recognize straight line rental expense over the life of the lease and any fair market value or Consumer Price Index rent escalations are recognized as variable lease expense in the period in which the obligation is incurred. In addition, we lease certain vehicles and equipment. Vehicle and equipment leases typically have lease terms ranging fromone toseven years.

We account for all leases, both operating and financing, in accordance with Accounting Standards Codification ("ASC") Topic 842, Leases ("ASC 842"). Our accounting policy provides that leases with an initial term of 12 months or less will not be included within the lease right-of-use assets and lease liabilities recognized on our Consolidated Balance Sheets. We recognize the lease payments for those leases with an initial term of 12 months or less in our Consolidated Statements of Operations on a straight-line basis over the lease term.

The lease right-of-use assets and related lease liabilities are classified as either operating or financing. Lease right-of-use assets are calculated as the net present value of future payments plus any capitalized initial direct costs less any tenant improvements or lease incentives. Lease liabilities are calculated as the net present value of future payments. In calculating the present value of the lease payments, we utilize the rate stated in the lease (in the limited circumstances when such rate is explicitly stated) or, if no rate is explicitly stated, we utilize a rate that reflects our securitized incremental borrowing rate by geography for the lease term. We account for nonlease components (which include common area maintenance, taxes, and insurance) with the related lease component. Any variable nonlease components are not included within the lease right-of-use asset and lease liability on our Consolidated Balance Sheets, and instead, are reflected as an expense in the period incurred.

Operating and financing lease right-of-use assets and lease liabilities as of December 31, 2025 and 2024 are as follows:

(1)At December 31, 2025 and 2024, these assets are comprised of approximately 98% real estate related assets (which include land, buildings, data center infrastructure and racking structures) and 2% non-real estate related assets (which include warehouse equipment, vehicles, furniture and fixtures and computer hardware and software).

(2)At December 31, 2025, these assets are comprised of approximately 56% real estate related assets and 44% non-real estate related assets. At December 31, 2024, these assets are comprised of approximately 58% real estate related assets and 42% non-real estate related assets.

(3)Financing lease right-of-use assets, current financing lease liabilities and long-term financing lease liabilities are included within Property, Plant and Equipment, Net, Current portion of long-term debt and Long-term Debt, net of current portion, respectively, within our Consolidated Balance Sheets.

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The components of the lease expense for the years ended December 31, 2025, 2024 and 2023 are as follows:

(1)Operating lease cost, the majority of which is included in Cost of sales, includes variable lease costs of $186,110, $163,916 and $142,154 for the years ended December 31, 2025, 2024 and 2023, respectively.

Weighted average remaining lease terms and discount rates as of December 31, 2025 and 2024 are as follows:

The estimated minimum future lease payments (receipts) as of December 31, 2025 are as follows:

(1)Estimated minimum future lease payments exclude variable common area maintenance charges, insurance and taxes.

Other information: Supplemental cash flow information relating to our leases for the years ended December 31, 2025, 2024 and 2023 is as follows:

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K. LONG-LIVED ASSETS

We review long-lived assets for impairment whenever events or changes in circumstances indicate the carrying amount of such assets may not be recoverable. Recoverability of these assets is determined by comparing the sum of the forecasted undiscounted net cash flows of the operation to which the assets relate to their carrying amount. The operations are generally distinguished by the business segment and geographic region in which they operate. If it is determined that we are unable to recover the carrying amount of the assets, the long-lived assets are written down, on a pro rata basis, to fair value. Fair value is determined based on discounted cash flows or appraised values, depending upon the nature of the assets. Long-lived assets, including finite-lived intangible assets, are amortized over their useful lives. Annually, or more frequently if events or circumstances warrant, we assess whether a change in the lives over which long-lived assets, including finite-lived intangible assets, are amortized is necessary.

Loss (gain) on disposal/write-down of property, plant and equipment, net for the years ended December 31, 2025, 2024 and 2023 is as follows:

(1)The gain recognized during the year ended December 31, 2023 is the result of our program to monetize a small portion of our industrial assets through sale and sale-leaseback transactions. The terms for these leases are consistent with the terms of our lease portfolio, which are disclosed in Note 2.j.

L. GOODWILL AND OTHER INDEFINITE-LIVED INTANGIBLE ASSETS

Goodwill and intangible assets with indefinite lives are not amortized but are reviewed annually for impairment, or more frequently if impairment indicators arise. Other than goodwill, we currently have no intangible assets that have indefinite lives and which are not amortized.

We test goodwill annually on October 1, and more frequently if impairment indicators arise that would require an interim test. We have performed our annual goodwill impairment review as of October 1, 2025, 2024 and 2023. We concluded that as of October 1, 2025, 2024 and 2023, goodwill was not impaired.

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REPORTING UNITS AS OF OCTOBER 1, 2025 and 2024

Our reporting units at which level we performed our goodwill impairment analysis as of October 1, 2025 and 2024 were as follows:

There were no changes to the composition of our reporting units between October 1, 2024 and December 31, 2024 and October 1, 2025 and December 31, 2025.

GOODWILL BY REPORTING UNIT AS OF DECEMBER 31, 2025 and 2024

The carrying value of goodwill, net for each of our reporting units described above as of December 31, 2025 and 2024 is as follows:

The fair value of our reporting units has generally been determined using a combined approach based on the present value of future cash flows (the "Discounted Cash Flow Model") and market multiples (the "Market Approach").

Changes in economic and operating conditions impacting these assumptions or changes in multiples could result in goodwill impairments in future periods. In conjunction with our annual goodwill impairment reviews, we reconcile the sum of the valuations of all of our reporting units to our market capitalization as of such dates.

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The changes in the carrying value of goodwill attributable to each reportable segment for the years ended December 31, 2025 and 2024 are as follows:

M. FINITE-LIVED INTANGIBLE ASSETS AND LIABILITIES

I. CUSTOMER AND SUPPLIER RELATIONSHIP INTANGIBLE ASSETS

Customer and supplier relationship intangible assets, which are acquired through either business combinations or acquisitions of customer relationships, are generally amortized over periods ranging from 10 to 30 years. Customer and supplier relationship intangible assets are recorded based upon estimates of their fair value.

II. CUSTOMER INDUCEMENTS

Payments that are made to a customer in order to terminate the customer’s storage of records with its current records management vendor ("Permanent Withdrawal Fees"), or direct payments to a customer for which no distinct benefit is received in return, are collectively referred to as "Customer Inducements". Customer Inducements are treated as a reduction of the transaction price over the associated contract terms, which range fromone to 10 years, and are included in storage and service revenue in the accompanying Consolidated Statements of Operations. If the customer terminates its relationship with us, the unamortized carrying value of the Customer Inducement intangible asset is charged to revenue. However, in the event of such termination, we generally collect, and record as revenue, Permanent Withdrawal Fees that generally equal or exceed the amount of the unamortized Customer Inducement intangible asset.

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III. DATA CENTER INTANGIBLE ASSETS AND LIABILITIES

Finite-lived intangible assets associated with our Global Data Center Business consist of the following:

DATA CENTER IN-PLACE LEASE INTANGIBLE ASSETS AND DATA CENTER TENANT RELATIONSHIP INTANGIBLE ASSETS

Data center in-place lease intangible assets ("Data Center In-Place Leases") and data center tenant relationship intangible assets ("Data Center Tenant Relationships") reflect the value associated with acquiring a data center operation with active tenants as of the date of acquisition. The value of Data Center In-Place Leases is determined based upon an estimate of the economic costs (such as lost revenues, tenant improvement costs, commissions, legal expenses and other costs to acquire new data center leases) avoided by acquiring a data center operation with active tenants. Data Center In-Place Leases are amortized over the weighted average remaining term of the acquired data center leases determined at the time of acquisition and range from five to 10 years. The value of Data Center Tenant Relationships is determined based upon an estimate of the economic costs avoided upon lease renewal of the acquired tenants, based upon expectations of lease renewal. Data Center Tenant Relationships are amortized over the weighted average remaining anticipated life of the relationship with the acquired tenant determined at the time of acquisition and range fromsix to 13 years.

DATA CENTER ABOVE-MARKET AND BELOW-MARKET IN-PLACE LEASE INTANGIBLE ASSETS

Data center above-market in-place lease intangible assets ("Data Center Above-Market Leases") and data center below-market in-place lease intangible assets ("Data Center Below-Market Leases") are recorded at the net present value of the difference between (i) the contractual amounts to be paid pursuant to each in-place lease and (ii) management’s estimate of the fair market lease rates for each corresponding in-place lease. Data Center Above-Market Leases and Data Center Below-Market Leases are amortized over the remaining non-cancellable term of the acquired in-place lease to storage revenue and range from 10 to 11 years.

The gross carrying amount and accumulated amortization of our finite-lived intangible assets as of December 31, 2025 and 2024, respectively, are as follows:

(1)Included in Customer and supplier relationship and other intangible assets in the accompanying Consolidated Balance Sheets.

(2)Data center lease-based intangible assets includes Data Center In-Place Leases, Data Center Tenant Relationships and Data Center Above-Market Leases.

(3)Included in Other (within Other Assets, Net) in the accompanying Consolidated Balance Sheets.

(4)Included in Other long-term liabilities in the accompanying Consolidated Balance Sheets.

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Amortization expense associated with finite-lived intangible assets, revenue reduction associated with the amortization of Customer Inducements and net revenue reduction associated with the amortization of Data Center Above-Market Leases and Data Center Below-Market Leases for the years ended December 31, 2025, 2024 and 2023 is as follows:

Estimated amortization expense for existing finite-lived intangible assets (excluding Contract Costs, as defined in Note 2.s.) is as follows:

N. DEFERRED FINANCING COSTS

Deferred financing costs are amortized over the life of the related debt. If debt is retired early, the related unamortized deferred financing costs are written off in the period the debt is retired and included as a component of Other expense (income), net. See Note 6.

O. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

Derivative instruments are measured at fair value and are recorded as either assets or liabilities in our Consolidated Balance Sheets. Periodically, we acquire derivative instruments that are intended to hedge either cash flows or values that are subject to foreign exchange or other market price risk and not for trading purposes. We have formally documented our hedging relationships, including identification of the hedging instruments and the hedged items, as well as our risk management objectives and strategies for undertaking each hedge transaction concurrently with the execution of the derivative instrument. Given the recurring nature of our revenues and the long-term nature of our asset base, we have the ability and the preference to use long-term, fixed interest rate debt to finance our business, thereby preserving our long-term returns on invested capital. We may use interest rate swaps as a tool to maintain our targeted level of fixed rate debt. In addition, we may enter into cross-currency swaps to hedge the variability of exchange rates between the United States dollar and the currencies of our foreign subsidiaries, as well as interest rates. We may also use borrowings in foreign currencies, either obtained in the United States or by our foreign subsidiaries, to hedge foreign currency risk associated with our international investments. Gains and losses realized as a result of the maturing or termination of our interest rate swaps and cross-currency swaps are reflected as operating cash flows within our Consolidated Statements of Cash Flows. As of December 31, 2025 and 2024, none of our derivative instruments contained credit-risk related contingent features. See Note 5.

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P. FAIR VALUE MEASUREMENTS

Entities are permitted under GAAP to elect to measure certain financial instruments and certain other items at either fair value or cost. We have elected the cost measurement option in all circumstances where we had an option.

Our financial assets or liabilities that are carried at fair value are required to be measured using inputs from the three levels of the fair value hierarchy. A financial asset or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels of the fair value hierarchy are as follows:

Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access at the measurement date.

Level 2—Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs).

Level 3—Unobservable inputs that reflect our assumptions about the assumptions that market participants would use in pricing the asset or liability.

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The assets and liabilities carried at fair value and measured on a recurring basis as of December 31, 2025 and 2024, respectively, are as follows:

(1)Money market funds and time deposits are measured based on quoted prices for similar assets and/or subsequent transactions.

(2)Certain trading securities are measured at fair value using quoted market prices.

(3)Certain trading securities are measured based on inputs other than quoted market prices that are observable.

(4)Derivative assets and liabilities include (i) interest rate swap agreements, and (ii) cross-currency swap agreements to hedge the variability of exchange rate impacts between the United States dollar and certain of our foreign functional currencies, including the Euro and the Canadian dollar. Our derivative financial instruments are measured using industry standard valuation models using market-based observable inputs, including interest rate curves, forward and spot prices for currencies and implied volatilities. See Note 5 for additional information on our derivative financial instruments.

(5)The balance as of December 31, 2025 primarily relates to the fair value of the deferred purchase obligation associated with the Regency Transaction (as defined in Note 3). The balance as of December 31, 2024 primarily relates to the fair values of the deferred purchase obligations associated with the Regency Transaction and the ITRenew Transaction (as defined below).

(6)The following is a rollforward of the Level 3 liabilities presented above for December 31, 2023 through December 31, 2025:

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The level 3 valuations of the deferred purchase obligations were determined utilizing either a Monte-Carlo simulation model or a discounted cash flow model and take into account our forecasted projections as they relate to the underlying performance of the respective businesses. On January 25, 2022, in order to expand our ALM operations, we acquired an approximately 80% interest in ITRenew (the "ITRenew Transaction"). The Monte-Carlo simulation model applied in assessing the fair value of the deferred purchase obligation associated with the ITRenew Transaction incorporates assumptions as to expected gross profits over the achievement period, including adjustments for the volatility of timing and amount of the associated revenue and costs, as well as discount rates that account for the risk of the arrangement and overall market risks. The discounted cash flow model applied in assessing the fair value of the deferred purchase obligation associated with the Regency Transaction incorporates assumptions as to expected revenue over the achievement period, including adjustments for volatility and timing, as well as discount rates that account for the risk of the arrangement and overall market risks. Any material change to these assumptions may result in a significantly higher or lower fair value of the related deferred purchase obligation.

There were no material items that were measured at fair value on a non-recurring basis for the years ended December 31, 2025 and 2024 other than (i) the reporting units as presented in our goodwill impairment analysis (as disclosed in Note 2.l.); (ii) assets acquired and liabilities assumed through our acquisitions; (iii) the redemption value of recently acquired noncontrolling interests; and (iv) contributions to our equity method investments, all of which are based on Level 3 inputs.

The fair value of our long-term debt, which was determined based on Level 2 and Level 3 inputs, is disclosed in Note 6. Long-term debt is measured at cost in our Consolidated Balance Sheets as of December 31, 2025 and 2024.

Q. NONCONTROLLING INTERESTS

Unaffiliated third parties own noncontrolling interests in certain of our consolidated subsidiaries. The classification of these ownership interests are evaluated under ASC 810, Consolidation and ASC 480, Distinguishing Liabilities from Equity. Ownership interests are classified as equity unless the underlying agreements contain provisions requiring classification as a liability or temporary equity. Noncontrolling interests are presented as a separate component of Iron Mountain Incorporated Stockholders’ (Deficit) Equity in the accompanying Consolidated Balance Sheets and Consolidated Statements of (Deficit) Equity.

Certain agreements with our noncontrolling interest shareholders contain put options which allow the noncontrolling interest shareholders to require us to purchase their respective interests in such subsidiaries at certain times and at purchase prices as stipulated in the underlying agreements (generally at fair value). These ownership interests, otherwise known as redeemable noncontrolling interests, are classified as temporary equity in our Consolidated Balance Sheets and Consolidated Statements of (Deficit) Equity. Redeemable noncontrolling interests are reported as temporary equity at the greater of their redemption value or the noncontrolling interest holders’ proportionate share of the underlying subsidiary’s net carrying value. Increases or decreases in the redemption value are offset against Additional Paid-in Capital. Changes in ownership interests that do not result in a loss of control are accounted for as equity transactions. If control is lost, the subsidiary’s assets, liabilities and noncontrolling interests are derecognized, and any resulting gain or loss is recorded in earnings.

The amount of consolidated net income attributable to noncontrolling interests, including redeemable noncontrolling interests, are presented in the accompanying Consolidated Statements of Operations and Consolidated Statements of Comprehensive Income (Loss).

When ownership interests are determined to be mandatorily redeemable, they are classified as liabilities and included as a component of Accrued expenses and other current liabilities or Other long-term liabilities on our Consolidated Balance Sheets, depending on the timing of the obligation.

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R. ACCUMULATED OTHER COMPREHENSIVE ITEMS, NET

The changes in Accumulated other comprehensive items, net for the years ended December 31, 2025, 2024 and 2023 are as follows:

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S. REVENUES

Our revenues consist of storage rental revenues and service revenues and are reflected net of sales and value-added taxes. Storage rental revenues, which are considered a key driver of financial performance for the storage and information management services industry, consist primarily of recurring periodic rental charges related to the storage of materials or data (generally on a per unit basis) that are typically retained by customers for many years and of revenues associated with our data center operations. Service revenues include charges for related service activities, the most significant of which include: (1) the handling of records, including the addition of new records, temporary removal of records from storage, refiling of removed records, customer termination and permanent withdrawal fees, project revenues and courier operations consisting primarily of the pickup and delivery of records upon customer request; (2) secure shredding of sensitive documents and the subsequent sale of shredded paper for recycling, the price of which can fluctuate from period to period; (3) the decommissioning, data erasure, processing and disposition, and recycling or sale of information technology ("IT") hardware and component assets; and (4) digital solutions, including the scanning, imaging and document conversion services of active and inactive records, consulting services and the sale of software as a service, including our Digital Experience Platform.

The majority of our revenue is recognized in accordance with Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers ("ASC 606"). Storage revenue for our Global Data Center Business is recognized in accordance with ASC Topic 842, Leases. For revenue recognized in accordance with ASC 606, customers are generally billed monthly based on contractually agreed-upon terms, and storage rental and service revenues are recognized in the month the respective storage rental or service is provided, in line with the transfer of control to the customer. When storage rental fees or services are billed in advance, amounts related to future storage rental or prepaid service contracts are accounted for as deferred revenue and recognized upon the transfer of control to the customer. Customer contracts generally include promises to provide monthly recurring storage and related services that are essentially the same over time and have the same pattern of transfer of control to the customer; therefore, most performance obligations represent a promise to deliver a series of distinct services over time (as determined for purposes of ASC 606, a "series"). For those contracts that qualify as a series, we apply the "right to invoice" practical expedient as we have a right to consideration from the customer in an amount that corresponds directly with the value of the underlying performance obligation transferred to the customer to date. Additionally, each purchasing decision is fully in the control of the customer; therefore, consideration beyond the current reporting period is variable and allocated to the specific period to which the consideration relates, which is consistent with the practical expedient. Revenue from product sales, the majority of which is IT asset sales, is recognized at the point in time at which control transfers to the customer, which is generally upon shipment.

Our Global Data Center Business features storage rental provided to the customer at contractually specified rates over a fixed contractual period. The revenue related to the storage component of our Global Data Center Business is recognized on a straight-line basis over the contract term in accordance with ASC 842. The revenue related to the service component of our Global Data Center Business that is not part of the combined single lease component is recognized in the period the related services are provided.

From time to time, we make payments to entities that are also customers under a revenue contract. These payments are primarily comprised of (i) Customer Inducements and (ii) payments to customers of our ALM business under revenue sharing arrangements for the remarketing of the customer's disposed IT assets. Customer Inducements do not represent payments for a distinct service, and, as such, are treated as a reduction of the transaction price and are amortized over the term of the contracts, which range fromone to 10 years. Payments for disposed IT assets are for a distinct good and, as such, are expensed as cost of sales in the period when the asset is sold and the corresponding revenue is recognized.

Certain costs to fulfill or obtain customer contracts and certain initial direct costs of obtaining leases, including the costs associated with the initial movement of customer records into physical storage and certain commission expenses, are collectively referred to as "Contract Costs". The following describes our significant Contract Costs:

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INTAKE COSTS (AND ASSOCIATED DEFERRED REVENUE)

The costs of the initial intake of customer records into physical storage ("Intake Costs"), are deferred and amortized as a component of depreciation and amortization in our Consolidated Statements of Operations generally over three years, consistent with the transfer of the performance obligation to the customer to which the asset relates. In instances where such Intake Costs are billed to the customer, the associated revenue is deferred and recognized over the same three-year period.

COMMISSIONS

Certain commission payments that are directly associated with obtaining long-term contracts are capitalized and amortized as a component of depreciation and amortization in our Consolidated Statements of Operations generally over three years, consistent with the transfer of the performance obligation to the customer to which the asset relates or the lease term. We also apply the practical expedient to expense certain commission payments as incurred when the amortization period for those commission payments is one year or less.

Contract Costs, which are included as a component of Other within Other Assets, Net as of December 31, 2025 and 2024 are as follows:

Amortization expense associated with the Intake Costs and other fulfillment costs asset and Commissions assets for the years ended December 31, 2025, 2024 and 2023 are as follows:

Estimated amortization expense for Contract Costs is as follows:

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Deferred revenue liabilities, which also includes deferred revenue accounted for under ASC 842 (as described below), are reflected as follows in our Consolidated Balance Sheets:

(1)The beginning balance of current and long-term deferred revenue for the year ended December 31, 2024 was $325,665 and $100,770, respectively.

(2)The current deferred revenue accounted for under ASC 842 is approximately $41,600 and $25,500 as of December 31, 2025 and 2024, respectively. Approximately half of this revenue is expected to be recognized over the next month, with the remainder expected to be recognized over the nexttwo to 12 months.

(3)The long-term deferred revenue accounted for under ASC 842 is approximately $141,100 and $95,000 as of December 31, 2025 and 2024, respectively.

In addition to our deferred revenue, we have remaining performance obligations related to certain customer contracts that have annual or monthly fixed fees with noncancelable terms. As of December 31, 2025, approximately $269,000 of remaining performance obligations are expected to be recognized as revenue over periods generally ranging fromone tofive years, with approximately 25% expected to be recognized within the next 12 months. As permitted under ASC 606, we do not disclose the value of remaining performance obligations for contracts as we have applied the "right to invoice" practical expedient, as described above.

DATA CENTER LESSOR CONSIDERATIONS

Our Global Data Center Business features storage rental provided to customers at contractually specified rates over a fixed contractual period. Our data center revenue contracts are accounted for in accordance with ASC 842. ASC 842 provides a practical expedient which allows lessors to account for nonlease components with the related lease component if both the timing and pattern of transfer are the same for nonlease components and the lease component, and the lease component, if accounted for separately, would be classified as an operating lease. The single combined component is accounted for under ASC 842 if the lease component is the predominant component. We have elected to take this practical expedient. The single combined component is presented as part of our storage rental revenue.

Storage rental revenue associated with our Global Data Center Business for the years ended December 31, 2025, 2024 and 2023 are as follows:

(1)Revenue associated with variable lease payments, primarily related to power and connectivity, included within storage rental revenue was approximately $172,000, $131,000 and $111,000 for the years ended December 31, 2025, 2024 and 2023, respectively.

The future minimum lease payments we expect to receive under non-cancellable data center operating leases for which we are the lessor, excluding month to month leases, for the next five years and thereafter are as follows:

(1)Future minimum lease payments we expect to receive exclude payments for contingent and variable costs such as taxes, insurance, common area maintenance and power and connectivity, which are included in our total storage revenue. These amounts also exclude approximately $3,317,000 in total expected future minimum lease payments for non-cancellable leases that have not yet commenced, which we expect to receive over a weighted average period of 16 years.

Part IV

T. STOCK-BASED COMPENSATION

We record stock-based compensation expense, utilizing the straight-line method, for the cost of stock options, restricted stock units ("RSUs"), and performance units ("PUs") (together, "Employee Stock-Based Awards"). Forfeitures are recorded in the period during which they occur. Our non-employee directors are considered employees for purposes of our Employee Stock-Based Awards and the associated reporting of these awards.

Our equity compensation plans generally provide that, upon a vesting change in control (as defined in each plan), any unvested options and other awards granted thereunder shall vest immediately if an employee is terminated as a result of the change in control or terminates their own employment for good reason (as defined in each plan). Other than in specified circumstances, no equity-based award will vest before the first anniversary of the date of grant.

On January 20, 2015, our stockholders approved the adoption of the Iron Mountain Incorporated 2014 Stock and Cash Incentive Plan, as amended (the "2014 Plan"). On May 29, 2025, our stockholders approved an amendment to the 2014 Plan, which (i) increases the number of shares of common stock authorized for issuance under the 2014 Plan by 4,600,000, from 20,750,000 to 25,350,000, and (ii) extends the termination date of the 2014 Plan from May 12, 2031 to May 29, 2035.

A total of 25,350,000 shares of common stock have been reserved for grants of options and other rights under our various stock incentive plans, including the 2014 Plan. The number of shares available for grant under our various stock incentive plans at December 31, 2025 was 7,617,011.

RETIREMENT ELIGIBLE CRITERIA

Our Employee Stock-Based Awards include the following retirement provision:

•Upon an employee’s retirement on or after attaining age 55 with at least five years of service, if the sum of (i) the award recipient’s age at retirement and (ii) the award recipient’s years of service with us totals at least 65, the award recipient is entitled to continued vesting of any outstanding Employee Stock-Based Awards, provided that their retirement occurs on or after a minimum of six months from the grant date (the "Retirement Criteria").

•Accordingly, (i) grants of Employee Stock-Based Awards to an employee who has met the Retirement Criteria on or before the date of grant, or will meet the Retirement Criteria before the six month anniversary in the year of the grant, will be expensed over six months from the date of grant and (ii) grants of Employee Stock-Based Awards to employees who will meet the Retirement Criteria during the award’s normal vesting period will be expensed between the date of grant and the date upon which the award recipient meets the Retirement Criteria.

•Stock options and RSUs granted to award recipients who meet the Retirement Criteria will be delivered to the award recipient based upon the original vesting schedule. If an award recipient retires and has met the Retirement Criteria, stock options will remain exercisable until the original expiration date of the stock options. PUs granted to award recipients who meet the Retirement Criteria will be delivered in accordance with the original vesting schedule of the applicable PU award and remain subject to the same performance conditions.

Stock-based compensation expense for Employee Stock-Based Awards included in Selling, general and administrative expenses in the accompanying Consolidated Statements of Operations for the years ended December 31, 2025, 2024 and 2023 is as follows:

As of December 31, 2025, unrecognized compensation cost related to the unvested portion of our Employee Stock-Based Awards, inclusive of our estimated achievement of the performance metrics, was $86,285 and is expected to be recognized over a weighted-average period of 1.9 years.

We issue shares of our common stock for the exercises of stock options, and the vesting of RSUs, PUs and shares of our common stock under our ESPP from unissued reserved shares.

Part IV

STOCK OPTIONS

Options are generally granted with exercise prices equal to the market price of the stock on the date of grant; however, in certain instances, options are granted at exercise prices greater than the market price of the stock on the date of grant. We issue options that become exercisable ratably over a period ofthree years from the date of grant and have a contractual life of 10 years from the date of grant, unless the holder’s employment is terminated sooner. Dividends and dividend equivalents are not paid with respect to stock options.

The fair value of stock options granted in 2025, 2024 and 2023 was $25.18, $22.58 and $10.98 per share, respectively. These values were estimated on the date of grant using the Black-Scholes option pricing model. The assumptions used for stock option grants in the years ended December 31, 2025, 2024 and 2023 are as follows:

(1)Expected volatility is calculated utilizing daily historical volatility over a period that equates to the expected life of the option.

(2)Risk-free interest rate is based on the United States Treasury interest rates whose term is consistent with the expected life (estimated period of time outstanding) of the stock options.

(3)Expected dividend yield is considered in the option pricing model and represents our annualized expected per share dividends over the trade price of our common stock at the date of grant.

(4)Expected life of the stock options granted is estimated using the historical exercise behavior of employees.

A summary of stock option activity for the year ended December 31, 2025 is as follows:

Part IV

RESTRICTED STOCK UNITS

Our RSUs generally have a vesting period ofthree years from the date of grant. However, RSUs granted to our non-employee directors vest immediately upon grant. All RSUs accrue dividend equivalents associated with the underlying stock as we declare dividends. Dividends will generally be paid to holders of RSUs in cash upon the vesting date of the associated RSU and will be forfeited if the RSU does not vest. The fair value of RSUs is the excess of the market price of our common stock at the date of grant over the holder's purchase price (which is typically zero).

The fair value of RSUs vested during the years ended December 31, 2025, 2024 and 2023 are as follows:

A summary of RSU activity for the year ended December 31, 2025 is as follows:

PERFORMANCE UNITS

The PUs we issue vest based on our performance against predefined operational performance and relative total shareholder return based targets over athree-year performance period. The vesting is subject to a minimum level of return on invested capital in the third year of the performance period, and the number of PUs earned is based on certain metrics determined at the outset of the performance period.

The number of PUs earned is based on:

•either (i) the revenue performance for each year averaged at the end of thethree-year performance period, or (ii) if (a) absolute Company total shareholder return is positive at the end of thethree-year performance period and (b) a predetermined revenue hurdle is achieved in the third year of the performance period, then the revenue performance achieved in the third year of the performance period; and

•the total return at the end of thethree-year performance period on our common stock relative to the companies comprising the Morgan Stanley Capital International ("MSCI") United States REIT Index.

The number of PUs earned will range from 0% to approximately 350% of the initial award.

Part IV

All of our PUs will be settled in shares of our common stock and are subject to cliff vesting three years from the date of the original PU grant. As detailed above, PUs granted are subject to the Retirement Criteria. PUs are generally expensed over thethree-year performance period, unless they are granted to a recipient who meets the Retirement Criteria, for which expense will be recognized as described above. PUs granted to recipients who meet the Retirement Criteria will continue to vest and be delivered in accordance with the original vesting schedule of the applicable PU award and remain subject to the same performance conditions.

All PUs accrue dividend equivalents associated with the underlying stock as we declare dividends. Dividends will generally be paid to holders of PUs in cash upon the settlement date of the associated PU and will be forfeited if the PU does not vest.

During the years ended December 31, 2025, 2024 and 2023, we issued 512,905,462,501 and 641,412 PUs, respectively. We forecast the likelihood of achieving the predefined targets for our PUs in order to calculate the expected PUs to be earned. We record a compensation charge based on either the forecasted PUs to be earned (during the performance period) or the actual PUs earned (at thethree-year anniversary of the grant date) over the vesting period for each of the awards. The fair value of PUs based on our performance against predefined targets is the excess of the market price of our common stock at the date of grant over the purchase price (which is typically zero). For PUs earned based on a market condition, we utilize a Monte Carlo simulation to estimate the fair value of these awards at the date of grant.

The fair value of earned PUs that vested during the years ended December 31, 2025, 2024 and 2023 is as follows:

A summary of PU activity for the year ended December 31, 2025 is as follows:

(1)Represents an increase or decrease in the number of original PUs awarded based on either the final performance criteria or market condition achievement at the end of the performance period of such PUs.

EMPLOYEE STOCK PURCHASE PLAN

We offer an Employee Stock Purchase Plan ("ESPP") in which participation is available to substantially all United States and Canadian employees who meet certain service eligibility requirements. Shares of our common stock may be purchased by eligible employees atsix-month intervals at 95% of the fair market price at the end of eachsix-month period, without a look-back feature, up to a maximum of 15% of their gross compensation during the offering period. We do not recognize compensation expense for the ESPP shares purchased. The number of shares of Common Stock authorized for issuance under our ESPP is 2,000,000. For the years ended December 31, 2025, 2024 and 2023, there were 80,068,82,244 and 120,647 shares, respectively, purchased under the ESPP. As of December 31, 2025, we have 708,545 shares available under the ESPP.

Part IV

U. ACQUISITION AND INTEGRATION COSTS

Acquisition and integration costs represent operating expenditures directly associated with the closing and integration activities of our business acquisitions that have closed, or are highly probable of closing, and include (i) advisory, legal and professional fees to complete business acquisitions and (ii) costs to integrate acquired businesses into our existing operations, including move, severance and system integration costs (collectively, "Acquisition and Integration Costs"). Acquisition and integration costs for the years ended December 31, 2025, 2024 and 2023 were $19,545, $35,842 and $25,875, respectively.

V. OTHER EXPENSE (INCOME), NET

Other expense (income), net for the years ended December 31, 2025, 2024 and 2023 consists of the following:

(1)The gain or loss on foreign currency transactions, calculated as the difference between the historical exchange rate and the exchange rate at the applicable measurement date, includes gains or losses primarily related to British pound sterling and Euro denominated intercompany obligations of our foreign subsidiaries to us and between our foreign subsidiaries, which are not considered permanently invested.

(2)Other, net for the year ended December 31, 2025 primarily consists of (i) a loss of approximately $13,800 due to the change in value of our deferred purchase obligations and other deferred payments and (ii) losses on our equity method investment.

(3)Other, net for the year ended December 31, 2024 primarily consists of (i) a loss of approximately $41,000 due to the change in value of our deferred purchase obligations and other deferred payments, (ii) approximately $29,200 in charges associated with the agreement to purchase the remaining interest in a joint venture and (iii) losses on our equity method investments.

(4)Other, net for the year ended December 31, 2023 consists primarily of a loss of approximately $38,000 associated with the remeasurement to fair value of our previously held equity interest in the joint venture we had formed with Clutter Intermediate, Inc. (the "Clutter JV"), as well as losses on our equity method investments and the change in value of our deferred purchase obligations.

W. INCOME TAXES

Accounting for income taxes requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the tax and financial reporting bases of assets and liabilities and for loss and credit carryforwards. Valuation allowances are provided when recovery of deferred tax assets does not meet the more likely than not standard as defined in GAAP. We have elected to recognize interest and penalties associated with uncertain tax positions as a component of the Provision (Benefit) for Income Taxes in the accompanying Consolidated Statements of Operations.

X. INCOME (LOSS) PER SHARE—BASIC AND DILUTED

Basic income (loss) per common share is calculated by dividing income (loss) by the weighted average number of common shares outstanding. The calculation of diluted income (loss) per share is consistent with that of basic income (loss) per share but gives effect to all potential common shares (that is, securities such as stock options, RSUs or PUs) that were outstanding during the period, unless the effect is antidilutive.

Part IV

The calculation of basic and diluted income (loss) per share for the years ended December 31, 2025, 2024 and 2023 is as follows:

Y. NEW ACCOUNTING PRONOUNCEMENTS

RECENTLY ADOPTED ACCOUNTING PRONOUNCEMENTS

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740), Improvements to Income Tax Disclosures ("ASU 2023-09") to provide disaggregated income tax disclosures on the rate reconciliation and income taxes paid. Further, certain requirements related to uncertain tax positions and unrecognized deferred tax liabilities are eliminated. We adopted ASU 2023-09 on January 1, 2025 on a prospective basis, and there was no material impact on our consolidated financial statements.

OTHER AS YET ADOPTED ACCOUNTING PRONOUNCEMENTS

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40), Disaggregation of Income Statement Expenses("ASU 2024-03"), which requires disclosure of additional information about specific expense categories in the notes to financial statements on an annual and interim basis. The amendments in this update should be applied on a prospective basis, with retrospective application permitted. The amendments in this update are effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods within fiscal years beginning after December 15, 2027, with early adoption permitted. We do not expect ASU 2024-03 to have a material impact on our consolidated financial statements.

In September 2025, the FASB issued ASU No. 2025-06, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software (“ASU 2025-06”). The ASU primarily updates the accounting for internal-use software by replacing former stage-based rules with a principles-based framework. Costs associated with internal-use software will be capitalized only when management has authorized and committed funding and it is probable that the project will be completed and the software will be used to perform the function intended. The amendments in this update are effective for annual reporting periods beginning after December 15, 2027 and interim reporting periods therein, with early adoption permitted, and can be applied either prospectively, retrospectively or on a modified prospective basis. We are currently evaluating the impact of ASU 2025-06 on our consolidated financial statements, but we do not expect it to be material.

Part IV

In December 2025, the FASB issued ASU No. 2025-11, Interim Reporting (Topic 270): Narrow-Scope Improvements ("ASU 2025-11"), which is intended to update the guidance in Topic 270 by improving navigability of the required interim disclosures, clarifying when that guidance is applicable and adding a principle that requires entities to disclose events since the end of the last annual reporting period that have a material impact on the entity. The amendments in this update are effective for the interim reporting periods within annual reporting periods beginning after December 15, 2027, with early adoption permitted, and can be applied either prospectively or retrospectively to any or all prior periods presented in the financial statements. We do not expect ASU 2025-11 to have a material impact on our quarterly condensed consolidated financial statements.

3. ACQUISITIONS

We account for acquisitions using the acquisition method of accounting, and, accordingly, the assets and liabilities acquired are recorded at their estimated fair values and the results of operations for each acquisition have been included in our consolidated results from their respective acquisition dates.

Allocations of the purchase price for acquisitions are based on estimates of the fair value of the net assets acquired and are subject to adjustment upon the finalization of the purchase price allocations. The accounting for business combinations requires estimates and judgments regarding expectations for future cash flows of the acquired business, and the allocations of those cash flows to identifiable tangible and intangible assets, in determining the assets acquired and liabilities assumed. The fair values assigned to tangible and intangible assets acquired and liabilities assumed, including contingent consideration, are based on management’s best estimates and assumptions, as well as other information compiled by management, including valuations that utilize customary valuation procedures and techniques. The estimates and assumptions underlying the initial valuations are subject to the collection of information necessary to complete the valuations within the measurement periods, which are up to one year from the respective acquisition dates.

As the valuation of certain assets and liabilities for purposes of purchase price allocations are preliminary in nature, they are subject to adjustment as additional information is obtained about the facts and circumstances regarding these assets and liabilities that existed at the acquisition date. Any adjustments to our estimates of purchase price allocation will be made in the periods in which the adjustments are determined and the cumulative effect of such adjustments will be calculated as if the adjustments had been completed as of the acquisition dates. Purchase price allocation adjustments recorded during the fourth quarter of 2025 and year ended December 31, 2025 were not material to our balance sheet or results from operations.

REGENCY TECHNOLOGIES

On January 3, 2024, in order to expand our ALM business, we acquired 100% of RSR Partners, LLC (doing business as Regency Technologies), an IT asset disposition services provider with operations throughout the United States, for an initial purchase price of approximately $200,000, subject to certain working capital adjustments at, and subsequent to, the closing, with $125,000 paid at closing, funded by borrowings under the Revolving Credit Facility, and the remaining $75,000 (the "January 2025 Payment"), paid in January 2025 (the "Regency Transaction"). The present value of the January 2025 Payment was included as a component of Accrued expenses and other current liabilities in our Consolidated Balance Sheet at December 31, 2024. The agreement for the Regency Transaction also includes a performance-based contingent consideration with a potential earnout range from zero to $200,000 based upon achievement of certain three-year cumulative revenue targets, which would be payable in 2027, if earned. The preliminary fair value estimate of this deferred purchase obligation as of the acquisition date was approximately $78,400. See Note 2.p. for details on the methodology used to establish the fair value. The fair value of the deferred purchase obligation is included as a component of Other long-term liabilities in our Consolidated Balance Sheets at December 31, 2025 and 2024. Subsequent increases or decreases in the fair value estimate of the deferred purchase obligation, as well as the accretion of the discount to present value, is included as a component of Other expense (income), net in our Consolidated Statements of Operations until the deferred purchase obligation is settled or paid. Subsequent to the acquisition, the results of Regency Technologies are included as a component of Corporate and Other (as defined in Note 10).

Part IV

4. INVESTMENTS

The following joint venture is accounted for as an equity method investment and is presented as a component of Other within Other assets, net in our Consolidated Balance Sheets. The carrying value and equity interest in our unconsolidated joint venture at December 31, 2025 and 2024 is as follows:

5. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

Derivative instruments we are party to include: (i) interest rate swap agreements (which are designated as cash flow hedges) and (ii) cross-currency swap agreements (which are designated as net investment hedges).

INTEREST RATE SWAP AGREEMENTS DESIGNATED AS CASH FLOW HEDGES

We utilize interest rate swap agreements designated as cash flow hedges to limit our exposure to changes in interest rates on a portion of our floating rate indebtedness. Certain of our interest rate swap agreements have notional amounts that will increase with the underlying hedged transaction. Under our interest rate swap agreements, we receive variable rate interest payments associated with the notional amount of each interest rate swap, based upon the one-month Secured Overnight Financing Rate ("SOFR"), in exchange for the payment of fixed interest rates as specified in the interest rate swap agreements. Our interest rate swap agreements are marked to market at the end of each reporting period, representing the fair values of the interest rate swap agreements, and any changes in fair value are recognized as a component of Accumulated other comprehensive items, net. Unrealized gains are recognized as assets, while unrealized losses are recognized as liabilities.

As of December 31, 2025 and 2024, we have approximately $1,349,000 and $1,482,000, respectively, in notional value outstanding on our interest rate swap agreements. As of December 31, 2025, our interest rate swap agreements have maturity dates ranging from February 2026 through May 2027.

CROSS-CURRENCY SWAP AGREEMENTS DESIGNATED AS A HEDGE OF NET INVESTMENT

We utilize cross-currency interest rate swaps to hedge the variability of exchange rate impacts between the United States dollar and certain of our foreign functional currencies, including the Euro and the Canadian dollar. As of December 31, 2025, our cross-currency interest rate swap agreements have maturity dates ranging from February 2026 through November 2026.

The notional values of our cross-currency interest rate swaps, by currency, as of December 31, 2025 and 2024 are as follows:

Part IV

5. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (CONTINUED)

We have designated these cross-currency swap agreements as hedges of net investments in our Euro and Canadian dollar denominated subsidiaries and they require an exchange of the notional amounts at maturity. These cross-currency swap agreements are marked to market at the end of each reporting period, representing the fair values of the cross-currency swap agreements, and any changes in fair value are recognized as a component of Accumulated other comprehensive items, net. Unrealized gains are recognized as assets while unrealized losses are recognized as liabilities. The excluded component of our cross-currency swap agreements is recorded in Accumulated other comprehensive items, net and amortized to interest expense on a straight-line basis.

The fair value of derivative instruments recognized in our Consolidated Balance Sheets as of December 31, 2025 and 2024, by derivative instrument, are as follows:

(1)Our derivative assets are included as a component of (i)Prepaid expenses and other or (ii) Other within Other assets, net and our derivative liabilities are included as a component of (i) Accrued expenses and other current liabilities or (ii) Other long-term liabilities in our Consolidated Balance Sheets. As of December 31, 2025, $63,634 is included within Accrued expenses and other current liabilities and $8,235 is included within Other long-term liabilities. As of December 31, 2024, $8,891 is included within Prepaid expenses and other, $19,201 is included within Other assets and $5,326 is included within Other long-term liabilities.

(2)As of December 31, 2025, cumulative net losses recorded within Accumulated other comprehensive items, net associated with our interest rate swap agreements are $10,959.

(3)As of December 31, 2025, cumulative net losses recorded within Accumulated other comprehensive items, net associated with our cross-currency swap agreements are $1,490, which include $63,607 related to the excluded component of our cross-currency swap agreements.

Unrealized (losses) gains recognized in Accumulated other comprehensive items, net during the years ending December 31, 2025, 2024 and 2023, by derivative instrument, are as follows:

Gains (losses) recognized in Net income during the years ending December 31, 2025, 2024 and 2023, by derivative instrument, are as follows:

Part IV

6. DEBT

Long-term debt is as follows:

Part IV

(1)The capital stock or other equity interests of our United States subsidiaries representing the substantial majority of our United States operations, and up to 66% of the capital stock or other equity interests of most of our first-tier foreign subsidiaries, are pledged to secure these debt instruments, together with all intercompany obligations (including promissory notes) of subsidiaries owed to us or to one of our United States subsidiary guarantors. In addition, Iron Mountain Canada Operations ULC has pledged 66% of the capital stock of its subsidiaries, and all intercompany obligations (including promissory notes) owed to or held by it, to secure the Revolving Credit Facility. The fair value (Level 2 and Level 3 of fair value hierarchy described at Note 2.p.) of these debt instruments approximates the carrying value, as borrowings under these debt instruments are based on current variable market interest rates (plus a margin that is subject to change based on our consolidated leverage ratio), as of December 31, 2025 and 2024 (collectively, the "Credit Agreement Collateral").

(2)The amount of debt for the Term Loan B (as defined below) reflects an unamortized original issue discount of $10,538 and $10,517 as of December 31, 2025 and 2024, respectively.

(3)The fair value (Level 2 of fair value hierarchy described at Note 2.p.) of this debt instrument approximates the carrying value as borrowings under this debt instrument are based on a current variable market interest rate.

(4)The amount of debt for the AUD Term Loan (as defined below) reflects an unamortized original issue discount of $1,756 and $842 as of December 31, 2025 and 2024, respectively.

(5)The fair values (Level 2 of fair value hierarchy described at Note 2.p.) of these debt instruments are based on quoted market prices for comparable notes on December 31, 2025 and 2024, respectively.

(6)Collectively, the "Unregistered Notes". The Unregistered Notes have not been registered under the Securities Act of 1933, as amended (the "Securities Act"), or under the securities laws of any other jurisdiction. Unless they are registered, the Unregistered Notes may be offered only in transactions that are exempt from registration under the Securities Act or the securities laws of any other jurisdiction.

(7)Iron Mountain (UK) PLC ("IM UK") is the direct obligor on the GBP Notes, which are fully and unconditionally guaranteed, on a senior basis, by IMI and IMI’s United States subsidiaries that represent the substantial majority of our United States operations (the "Note Guarantors"). These guarantees are joint and several obligations of IMI and the Note Guarantors. The remainder of our subsidiaries do not guarantee the GBP Notes. The full amount of the GBP Notes is classified within the current portion of long-term debt in our Consolidated Balance Sheet at December 31, 2024.

(8)Collectively, the "Parent Notes". IMI is the direct obligor on the Parent Notes, which are fully and unconditionally guaranteed, on a senior basis, by the Note Guarantors. These guarantees are joint and several obligations of the Note Guarantors. The remainder of our subsidiaries do not guarantee the Parent Notes.

(9)Iron Mountain Information Management Services, Inc. ("IMIM Services") is the direct obligor on the 5% Notes due 2032, which are fully and unconditionally guaranteed, on a senior basis, by IMI and the Note Guarantors. These guarantees are joint and several obligations of IMI and the Note Guarantors. The remainder of our subsidiaries do not guarantee the 5% Notes due 2032.

(10)We believe the fair value (Level 2 of fair value hierarchy described at Note 2.p.) of this debt approximates its carrying value as these borrowings are based on current market interest rates. This debt includes the following:

(1)Bear interest at approximately 4.2% and 4.4% at December 31, 2025 and 2024, respectively, and includes $50,000 outstanding under our Mortgage Securitization Program at both December 31, 2025 and 2024.

(2)Bear a weighted average interest rate of 5.6% and 5.2% at December 31, 2025 and 2024, respectively.

(3)These notes and other obligations, which were assumed by us as a result of certain acquisitions, bear a weighted average interest rate of 6.5% and 7.2% at December 31, 2025 and 2024, respectively.

(11) The Accounts Receivable Securitization Special Purpose Subsidiaries (as defined below) are the obligors under this program.

A. CREDIT AGREEMENT

Our credit agreement (the "Credit Agreement") consists of a revolving credit facility (the "Revolving Credit Facility"), a term loan A facility (the "Term Loan A") and a term loan B facility (the "Term Loan B").

During the year ended December 31, 2025, we took the following actions regarding our Credit Agreement:

•On June 18, 2025, we amended the Credit Agreement, which resulted in:

◦an increase in the principal amount of the Term Loan A from $218,750 to $500,000.

•On November 13, 2025, we amended the Credit Agreement, which resulted in:

◦an increase in the principal amount of the Term Loan B from approximately $1,836,700 to $2,036,700.

Part IV

In connection with the November 13, 2025 amendment, we paid original issue discount fees of approximately $1,750.

The Revolving Credit Facility enables IMI and certain of its subsidiaries to borrow an aggregate outstanding amount not to exceed $2,750,000 in United States dollars and (subject to sublimits) Canadian dollars. Additionally, the Credit Agreement permits us to incur incremental indebtedness thereunder by adding new term loans or revolving loans or by increasing the principal amount of any existing loans thereunder. The Revolving Credit Facility and the Term Loan A are scheduled to mature on March 18, 2030, at which point all obligations become due. The Term Loan A, which was fully drawn as of December 31, 2025, is to be paid in quarterly installments in an amount equal to approximately $6,250 per quarter. The Term Loan B is scheduled to mature on January 31, 2031, at which point all obligations become due. The Term Loan B, which was fully drawn as of December 31, 2025, is to be paid in quarterly installments in an amount equal to approximately $5,182 per quarter.

IMI and certain subsidiaries of IMI that represent the substantial majority of our operations in the United States, Canada and the United Kingdom guarantee all obligations under the Credit Agreement. The interest rate on borrowings under the Revolving Credit Facility varies depending on our choice of interest rate benchmark and currency options, plus an applicable margin, which varies based on our consolidated leverage ratio. The Term Loan A and the Term Loan B bear interest at the SOFR plus 1.75% and the SOFR plus 2.00%, respectively. Additionally, the Credit Agreement requires the payment of a commitment fee on the unused portion of the Revolving Credit Facility, which fee ranges from 0.2% to 0.3% based on our consolidated leverage ratio.

As of December 31, 2025, we had $751,500, $487,500 and $2,031,495 outstanding under the Revolving Credit Facility, the Term Loan A and the Term Loan B, respectively. As of December 31, 2025, we had various outstanding letters of credit totaling $12,398 under the Revolving Credit Facility. The remaining amount available for borrowing under the Revolving Credit Facility as of December 31, 2025, which is based on IMI’s leverage ratio, the last 12 months' earnings before interest, taxes, depreciation and amortization and rent expense ("EBITDAR"), other adjustments as defined in the Credit Agreement and current external debt, was $1,986,102 (which amount represents the maximum availability as of such date). Available borrowings under the Revolving Credit Facility are subject to compliance with our indenture covenants as discussed below. The weighted average interest rates in effect under the Revolving Credit Facility as of December 31, 2025 and 2024 were 5.7% and 6.3%, respectively. The interest rates in effect under the Term Loan A as of December 31, 2025 and 2024 were 5.5% and 6.1%, respectively. The interest rates in effect under the Term Loan B as of December 31, 2025 and 2024 were 5.8% and 6.4%, respectively.

Part IV

B. DATA CENTER DEBT AGREEMENTS

As our Global Data Center Business continues to expand, we have entered into debt agreements in order to partially finance the construction of various data centers. These agreements primarily consist of term loan facilities with the following terms:

(1)All obligations will become due on the specified maturity dates. Each agreement, with the exception of the Virginia 4/5 Term Loans due 2030, includestwo one-year options that allow us to extend the initial maturity date, subject to the conditions specified in the agreements.

(2)Iron Mountain Data Centers Virginia 3, LLC, a wholly-owned subsidiary of IMI, has a credit agreement that includes a term loan facility (the "Virginia 3 Term Loans") and a letter of credit facility (collectively, the "Virginia 3 Credit Agreement"). The Virginia 3 Credit Agreement is secured by the equity interests and assets of Iron Mountain Data Centers Virginia 3, LLC. As of December 31, 2025 and 2024, the Virginia 3 Term Loans have a weighted average interest rate of 6.2% and 6.7%, respectively.

(3)Iron Mountain Data Centers Virginia 7, LLC, a wholly-owned subsidiary of Iron Mountain Data Centers Virginia 6/7 JV, LLC, has a credit agreement that includes a term loan facility (the "Virginia 7 Term Loans") and a letter of credit facility (collectively, the "Virginia 7 Credit Agreement"). The Virginia 7 Credit Agreement is secured by the equity interests and assets of Iron Mountain Data Centers Virginia 7, LLC. As of December 31, 2025 and 2024, the interest rate in effect under the Virginia 7 Credit Agreement was 7.1% and 7.0%, respectively.

(4)Iron Mountain Data Centers Virginia 6, LLC, a wholly-owned subsidiary of Iron Mountain Data Centers Virginia 6/7 JV, LLC, has a credit agreement that includes a term loan facility (the "Virginia 6 Term Loans") and a letter of credit facility (collectively, the "Virginia 6 Credit Agreement"). The Virginia 6 Credit Agreement is secured by the equity interests and assets of Iron Mountain Data Centers Virginia 6, LLC. As of December 31, 2025 and 2024, the interest rate in effect under the Virginia 6 Credit Agreement was 7.1% and 7.1%, respectively.

(5)At December 31, 2024, Iron Mountain Data Centers Virginia 4/5 Subsidiary, LLC, a wholly-owned subsidiary of Iron Mountain Data Centers Virginia 4/5 JV, LP, had a credit agreement that included a term loan facility (the "Virginia 4/5 Term Loans due 2025") and a letter of credit facility (collectively, the "Virginia 4/5 Credit Agreement"). On November 3, 2025, Iron Mountain Data Centers Virginia 4/5 Subsidiary, LLC entered into a term loan agreement (the "Virginia 4/5 Term Loans due 2030"). Total net proceeds from the Virginia 4/5 Term Loans due 2030 were used to repay the Virginia 4/5 Term Loans due 2025. The Virginia 4/5 Term Loans due 2030 is secured by the property of Iron Mountain Data Centers Virginia 4/5 Subsidiary, LLC. The Virginia 4/5 Term Loans due 2025 bore interest at SOFR plus a credit spread adjustment of 0.1% plus 1.625% until its extinguishment in November 2025. The interest rate in effect under the Virginia 4/5 Term Loans due 2025 as of December 31, 2024 was 5.1%.

Part IV

C. NOTES ISSUED UNDER INDENTURES

Each series of notes shown below (i) is effectively subordinated to all of our secured indebtedness, including under the Credit Agreement, to the extent of the value of the collateral securing such indebtedness, (ii) ranks pari passu in right of payment with each other and with debt outstanding under the Credit Agreement, the senior notes shown below and other "senior debt" we incur from time to time and (iii) is structurally subordinated to all liabilities of our subsidiaries that do not guarantee such series of notes.

The key terms of our indentures are as follows:

(1)We may redeem the notes at any time, at our option, in whole or in part. Prior to the par call date, we may redeem the notes at the redemption price or make-whole premium specified in the applicable indenture, together with accrued and unpaid interest to, but excluding, the redemption date. On or after the par call date, we may redeem the notes at a price equal to 100% of the principal amount being redeemed, together with accrued and unpaid interest to, but excluding, the redemption date.

Each of the indentures for the notes provides that we must repurchase, at the option of the holders, the notes at 101% of their principal amount, plus accrued and unpaid interest, upon the occurrence of a "Change of Control", which is defined in each respective indenture. Except for required repurchases upon the occurrence of a Change of Control or in the event of certain asset sales, each as described in the respective indenture, we are not required to make sinking fund or redemption payments with respect to any of the notes.

SEPTEMBER 2025 OFFERING

On September 10, 2025, IMI completed a private offering of:

The Euro Notes were issued at par and have a contractual interest rate of 4.75%. The total net proceeds from the issuance, after deducting the initial purchasers' commissions, of approximately 1,188,000 Euros (or $1,390,651, based upon the exchange rate between the Euro and the United States dollar on September 10, 2025 (the settlement date for the Euro Notes)), were used to repay the GBP Notes and a portion of the outstanding borrowings under the Revolving Credit Facility. As of December 31, 2025, we had 1,200,000 Euros (or $1,408,825, based upon the exchange rate between the United States dollar and the Euro as of December 31, 2025) outstanding on the Euro Notes.

Part IV

D. AUSTRALIAN DOLLAR TERM LOAN

Iron Mountain Australia Group Pty, Ltd., a wholly-owned subsidiary of IMI, has an AUD term loan (the "AUD Term Loan"). On June 25, 2025, we amended the AUD Term Loan, which resulted in:

•an extension of the maturity date from September 30, 2026 to September 30, 2030,

•an increase in the original principal amount from 350,000 Australian dollars to 400,000 Australian dollars and

•a decrease in the interest rate from BBSY (an Australian benchmark variable interest rate) plus 3.625% to BBSY plus 3.500%.

The amended loan was issued at 99.5% of par. Principal payments on the AUD Term Loan are to be paid in quarterly installments in an aggregate amount of 10,000 Australian dollars per year, with the remaining balance due September 2030. The AUD Term Loan is guaranteed by Iron Mountain Australia Group Pty, Ltd. and certain other Australian subsidiaries (the "Australia Group Guarantors") and by the guarantors of the Credit Agreement. The AUD Term Loan is secured by the capital stock and assets of the Australia Group Guarantors and by the Credit Agreement Collateral.

E. UK REVOLVING CREDIT FACILITY

Part IV

F. ACCOUNTS RECEIVABLE SECURITIZATION PROGRAM

We participate in an accounts receivable securitization program (the "Accounts Receivable Securitization Program") involving several of our wholly-owned subsidiaries and certain financial institutions. Under the Accounts Receivable Securitization Program, certain of our subsidiaries sell substantially all of their United States accounts receivable balances to our wholly-owned special purpose entities, Iron Mountain Receivables QRS, LLC and Iron Mountain Receivables TRS, LLC (the "Accounts Receivable Securitization Special Purpose Subsidiaries"). The Accounts Receivable Securitization Special Purpose Subsidiaries use the accounts receivable balances to collateralize loans obtained from certain financial institutions. The Accounts Receivable Securitization Special Purpose Subsidiaries are consolidated subsidiaries of IMI. The Accounts Receivable Securitization Program is accounted for as a collateralized financing activity, rather than a sale of assets, and therefore: (i) accounts receivable balances pledged as collateral are presented as assets and borrowings are presented as liabilities on our Consolidated Balance Sheets, (ii) our Consolidated Statements of Operations reflect the associated charges for bad debt expense related to pledged accounts receivable (a component of selling, general and administrative expenses) and reductions to revenue due to billing and service related credit memos issued to customers and related reserves, as well as interest expense associated with the collateralized borrowings and (iii) receipts from customers related to the underlying accounts receivable are reflected as operating cash flows and borrowings and repayments under the collateralized loans are reflected as financing cash flows within our Consolidated Statements of Cash Flows. Iron Mountain Information Management, LLC retains the responsibility of servicing the accounts receivable balances pledged as collateral for the Accounts Receivable Securitization Program and IMI provides a performance guaranty. The maximum availability allowed is limited by eligible accounts receivable, as defined under the terms of the Accounts Receivable Securitization Program. The Accounts Receivable Securitization Program is secured by a substantial majority of our net receivables in the United States.

G. CASH POOLING

Certain of our subsidiaries participate in cash pooling arrangements (the "Cash Pools") to help manage global liquidity requirements. We utilize the following Cash Pools: (i)two Cash Pools with ING Bank NV (doing business as Bank Mendes Gans), one of which we use to manage global liquidity requirements for our qualified REIT subsidiaries ("QRSs") and the other for our taxable REIT subsidiaries ("TRSs"), (ii)two Cash Pools with JP Morgan Chase Bank, N.A. ("JPM"), one of which we use to manage liquidity requirements for our QRSs in the Asia Pacific region and the other for our TRSs in the Asia Pacific region and (iii)two Cash Pools with JPM, one of which we use to manage liquidity requirements for our QRSs in the Europe, Middle East, and Africa regions and the other for our TRSs in the Europe, Middle East, and Africa regions.

Under each of the Cash Pools, cash deposited by participating subsidiaries with certain financial institutions is pledged as security against the debit balances of other participating subsidiaries with legal rights of offset provided to the financial institutions. Therefore, such amounts are presented in our Consolidated Balance Sheets on a net basis. Each subsidiary receives interest on the cash balances held on deposit or pays interest on its debit balances based on an applicable rate as defined in the Cash Pools.

The net cash position balances as of December 31, 2025 and 2024 are reflected as Cash and cash equivalents in our Consolidated Balance Sheets.

Part IV

H. LETTERS OF CREDIT

As of December 31, 2025, we had outstanding letters of credit totaling $80,751, of which $12,398 reduce our borrowing capacity under the Revolving Credit Facility (as described above). The letters of credit expire at various dates between February 2026 and May 2027.

I. DEBT COVENANTS

The Credit Agreement, our bond indentures and other agreements governing our indebtedness contain certain restrictive financial and operating covenants, including covenants that restrict our ability to complete acquisitions, pay cash dividends, incur indebtedness, make investments, sell assets and take other specified corporate actions. The covenants do not contain a rating trigger. Therefore, a change in our debt rating would not trigger a default under the Credit Agreement, our bond indentures or other agreements governing our indebtedness. The Credit Agreement requires that we satisfy a net total lease adjusted leverage ratio and a fixed charge coverage ratio on a quarterly basis, and our bond indentures require that, among other things, we satisfy a leverage ratio (not lease adjusted) or a fixed charge coverage ratio (not lease adjusted), as a condition to taking actions such as paying dividends and incurring indebtedness.

The Credit Agreement uses EBITDAR-based calculations and the bond indentures use earnings before income, taxes, depreciation and amortization ("EBITDA") based calculations as the primary measures of financial performance for purposes of calculating leverage and fixed charge coverage ratios. The EBITDAR- and EBITDA-based leverage calculations include our consolidated subsidiaries, other than those we have designated as "Unrestricted Subsidiaries" as defined in the Credit Agreement and bond indentures. Generally, the Credit Agreement and the bond indentures use a trailing four fiscal quarter basis for purposes of the relevant calculations and require certain adjustments and exclusions for purposes of those calculations, which make the calculation of financial performance under the Credit Agreement and bond indentures not directly comparable to Adjusted EBITDA as presented herein. We are in compliance with our leverage and fixed charge coverage ratios under the Credit Agreement, our bond indentures and other agreements governing our indebtedness as of December 31, 2025. Noncompliance with these leverage and fixed charge coverage ratios would have a material adverse effect on our financial condition and liquidity.

J. MATURITIES OF LONG-TERM DEBT (GROSS OF DISCOUNTS) ARE AS FOLLOWS:

Part IV

7. COMMITMENTS AND CONTINGENCIES

A. PURCHASE COMMITMENTS

We have certain contractual obligations related to purchase commitments which require minimum payments as follows:

(1)Purchase commitments (i) include obligations related principally to software maintenance and support services and (ii) exclude our operating and financing lease obligations (see Note 2.j.) and our deferred purchase obligations (see Note 2.p.).

In addition to the above, as of December 31, 2025, we have contractual commitments of approximately $1,085,725 for future construction costs associated with the expansion of our Global Data Center Business that are expected to be incurred over the nextone totwo years.

B. SELF-INSURED LIABILITIES

We are self-insured up to certain limits for costs associated with workers’ compensation claims, vehicle accidents, property and general business liabilities and benefits paid under employee healthcare and short-term disability programs. At December 31, 2025 and 2024, there were approximately $44,300 and $45,200, respectively, of self-insurance accruals reflected in Accrued expenses on our Consolidated Balance Sheets. The measurement of these costs requires the consideration of historical cost experience and judgments about the present and expected levels of cost per claim. We account for these costs primarily through actuarial methods, which develop estimates of the undiscounted liability for claims incurred, including those claims incurred but not reported. These methods provide estimates of future claim costs based on claims incurred as of the balance sheet date.

C. LITIGATION—GENERAL

We are involved in litigation from time to time in the ordinary course of business, including litigation arising from damage to customer assets in our facilities caused by fires and other natural disasters. A portion of the defense and/or settlement costs associated with such litigation is covered by various commercial liability insurance policies purchased by us and, in limited cases, indemnification from third parties. Our policy is to establish reserves for loss contingencies when the losses are both probable and reasonably estimable. We record legal costs associated with loss contingencies as expenses in the period in which they are incurred. While the outcome of litigation is inherently uncertain, we do not believe any current litigation will have a material adverse effect on our consolidated financial condition, results of operations or cash flows.

Part IV

8. STOCKHOLDERS' EQUITY MATTERS

DIVIDENDS

Our board of directors has adopted a dividend policy under which we have paid, and in the future intend to pay, quarterly cash dividends on our common stock. The amount and timing of future dividends will continue to be subject to the approval of our board of directors, in its sole discretion, and to applicable legal requirements.

In 2023, 2024 and 2025, our board of directors declared the following dividends:

On February 12, 2026, we declared a dividend to our stockholders of record as of March 16, 2026 of $0.8640 per share, payable on April 3, 2026.

During the years ended December 31, 2025, 2024 and 2023, we declared dividends in an aggregate and per share amount, based on the weighted average number of common shares outstanding during each respective year, as follows:

Part IV

8. STOCKHOLDERS’ EQUITY MATTERS (CONTINUED)

For federal income tax purposes, distributions to our stockholders are generally treated as nonqualified ordinary dividends (potentially eligible for the lower effective tax rates available for "qualified REIT dividends"), qualified ordinary dividends or return of capital. The United States Internal Revenue Service requires historical C corporation earnings and profits to be distributed prior to any REIT distributions, which may affect the character of each distribution to our stockholders, including whether and to what extent each distribution is characterized as a qualified or nonqualified ordinary dividend. In addition, certain of our distributions qualify as capital gain distributions. For the years ended December 31, 2025, 2024 and 2023, the dividends we paid on our common shares were classified as follows:

(1)During the year ended December 31, 2023, the percentage of our dividends that was classified as qualified ordinary dividends for federal income tax purposes primarily related to the distribution of historical C corporation earnings and profits during the year ended December 31, 2023.

NONCONTROLLING INTERESTS

In December 2025, we entered into an agreement with a partner to form our Iron Mountain Data Centers Arizona 3 JV, LP joint venture, which resulted in an initial Noncontrolling interest of approximately $74,800 recorded in our Consolidated Balance Sheet at December 31, 2025.

During the quarter ended September 30, 2024, a put option available to our partner in our Iron Mountain Data Centers Virginia 4/5 JV, LP joint venture expired, triggering a change in the presentation of the related noncontrolling interest. Prior to September 30, 2024, the noncontrolling interest of approximately $53,400 was presented as Redeemable noncontrolling interests in our Consolidated Balance Sheets. Our partner's interest is now presented as Noncontrolling interests in our Consolidated Balance Sheets at December 31, 2025 and 2024.

In August 2024, we entered into an agreement with a partner to form our Iron Mountain Data Centers Virginia 6/7 JV, LLC joint venture, which resulted in an initial Noncontrolling interest of approximately $103,100 recorded in our Consolidated Balance Sheet at September 30, 2024.

9. INCOME TAXES

We have been organized and have operated as a REIT effective beginning with our taxable year that ended on December 31, 2014. As a REIT, we are generally permitted to deduct from our federal taxable income the dividends we pay to our stockholders. The income represented by such dividends is not subject to federal taxation at the entity level but is taxed, if at all, at the stockholder level. The income of our domestic TRSs, which hold our domestic operations that may not be REIT-compliant as currently operated and structured, is subject, as applicable, to federal and state corporate income tax. In addition, we and our subsidiaries continue to be subject to foreign income taxes in other jurisdictions in which we have business operations or a taxable presence, regardless of whether assets are held or operations are conducted through subsidiaries disregarded for federal income tax purposes or TRSs. We will also be subject to a separate corporate income tax on any gains recognized on the sale or disposition of any asset previously owned by a C corporation during a five-year period after the date we first owned the asset as a REIT asset that are attributable to "built-in gains" with respect to that asset on that date. We will also be subject to a built-in gains tax on our depreciation recapture recognized into income as a result of accounting method changes in connection with our acquisition activities. If we fail to remain qualified for taxation as a REIT, we will be subject to federal income tax at regular corporate income tax rates. Even if we remain qualified for taxation as a REIT, we may be subject to some federal, state, local and foreign taxes on our income and property in addition to taxes owed with respect to our TRS operations. In particular, while state income tax regimes often parallel the federal income tax regime for REITs, many states do not completely follow federal rules and some do not follow them at all.

Part IV

The significant components of our deferred tax assets and deferred tax liabilities as of December 31, 2025 and 2024 are presented below:

The deferred tax assets and deferred tax liabilities as of December 31, 2025 and 2024 are presented below:

At December 31, 2025, we have federal net operating loss carryforwards of $116,233 and disallowed interest expense carryforwards of $185,852 both of which can be carried forward indefinitely, and of which $109,868 and $64,556, respectively, are expected to be realized to reduce future federal taxable income. We have assets for foreign net operating losses of $146,255 and foreign disallowed interest expense carryforwards of $46,625, with various expiration dates (and in some cases no expiration date), subject to valuation allowances of approximately 77.5% and 26.8%, respectively. If actual results differ unfavorably from certain of our estimates used, we may not be able to realize all or part of our net deferred income tax assets and additional valuation allowances may be required. Although we believe our estimates are reasonable, no assurance can be given that our estimates reflected in the tax provisions and accruals will equal our actual results. These differences could have a material impact on our income tax provision and operating results in the period in which such determination is made.

A rollforward of the valuation allowance is as follows:

(1)Other decreases and increases in valuation allowances are primarily related to changes in foreign currency exchange rates and prior year acquisitions.

(2)In connection with the implementation of the Organization for Economic Co-operation and Development (the "OECD") global minimum tax initiative known as Pillar Two, any existing deferred taxes not disclosed in our 2023 financial statements will not be available in the future to reduce tax otherwise due under Pillar Two. Accordingly, in 2023, the above table includes the tax effects of these non-United States tax loss carryforwards, which were not previously disclosed in the prior years due to the remote possibility of realization, offset with a full valuation allowance.

Part IV

The components of Net Income (Loss) Before Provision (Benefit) for Income Taxes for the years ended December 31, 2025, 2024 and 2023 are as follows:

The Provision (Benefit) for Income Taxes for the years ended December 31, 2025, 2024 and 2023 consist of the following components:

Part IV

Pursuant to the disclosure requirements of ASU 2023-09, a reconciliation of Provision (Benefit) for Income Taxes and the "expected" tax provision computed by applying the current federal statutory tax rate of 21.0% to Net Income (Loss) Before Provision (Benefit) for Income Taxes for the year ended December 31, 2025 is as follows:

Part IV

(1)In 2025, state and local taxes in Tennessee, Pennsylvania and Texas made up the majority (greater than 50%) of the tax effect in this category.

A reconciliation of Provision (Benefit) for Income Taxes and the "expected" tax provision computed by applying the current federal statutory tax rate of 21.0% to Net Income (Loss) Before Provision (Benefit) for Income Taxes for the years ended December 31, 2024 and 2023, respectively, is as follows:

Our effective tax rates for the years ended December 31, 2025, 2024 and 2023 were 27.9%,24.9% and 17.6%, respectively. Our effective tax rate is subject to variability in the future due to, among other items: (i) changes in the mix of income between our QRSs and our TRSs, as well as among the jurisdictions in which we operate, (ii) tax law changes, (iii) volatility in foreign exchange gains and losses, (iv) the timing of the establishment and reversal of tax reserves, (v) our ability to utilize net operating losses and interest expenses that we generate and (vi) the taxability or deductibility of significant transactions.

Part IV

The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate were:

As a REIT, we are entitled to a deduction for dividends paid, resulting in a substantial reduction of federal income tax expense. As a REIT, substantially all of our income tax expense will be incurred based on the earnings generated by our foreign subsidiaries and our domestic TRSs.

We provide for foreign withholding taxes on the undistributed earnings of our foreign TRSs because it is not our intention to reinvest the undistributed earnings of our foreign TRSs indefinitely outside the United States. As a REIT, future repatriation of incremental undistributed earnings of our foreign subsidiaries will not be subject to federal or state income tax.

The OECD has issued proposals that change long-standing tax principles, including a global minimum tax rate of 15% ("Pillar Two"). While the United States has not enacted legislation to effectuate Pillar Two, Iron Mountain operates in many foreign jurisdictions that have enacted legislation to implement Pillar Two. Pillar Two became applicable for Iron Mountain beginning in 2024. Recent G7 Country (Canada, France, Germany, Italy, Japan and the UK) statements released a side-by-side ("SbS") safe harbor that exempts certain U.S.-parented groups from these rules. The side-by-side Safe Harbor provides that Multinational Enterprise G Groups with an Ultimate Parent Entity in a jurisdiction with qualified SbS regime will not be subject to the Income Inclusion Rule and Undertaxed Profits Rule if they elect the SbS Safe Harbor, applicable as of the beginning of 2026. Since we do not have material operations in jurisdictions with tax rates lower than the Pillar Two minimum, we are not expecting a material impact on our effective tax rate, corporate tax liabilities or cash tax liabilities. We continue to monitor United States and global legislative actions as well as administrative guidance related to Pillar Two for potential impacts.

On July 4, 2025, President Trump signed into law the reconciliation bill, commonly referred to as the One Big Beautiful Bill Act ("OBBBA"). The OBBBA introduces several changes to U.S. federal income tax law, such as suspending the capitalization and amortization of domestic research and development expenditures and reinstating bonus depreciation. It also modifies the deductions available for net controlled foreign corporation tested income (formerly referred to as "global intangible low-taxed income") from non-U.S. subsidiaries and changes the limitations on deductible interest. Under the prior law, not more than 20% of the value of a REIT’s total assets at the end of any quarter could be represented by securities of one or more taxable REIT subsidiaries; the OBBBA increased this threshold to 25% effective January 1, 2026. The effective dates of the OBBBA provisions range from 2025 through 2027. We do not expect the OBBBA provisions to have a material impact on our consolidated financial statements.

Part IV

The evaluation of an uncertain tax position is a two-step process. The first step is a recognition process whereby we determine whether it is more likely than not that a tax position will be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. The second step is a measurement process whereby a tax position that meets the more likely than not recognition threshold is calculated to determine the amount of benefit to recognize in the financial statements. The tax position is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement.

We have elected to recognize interest and penalties associated with uncertain tax positions as a component of the Provision (Benefit) for Income Taxes in the accompanying Consolidated Statements of Operations. We recorded decreases of $326, $375 and $2,557 for gross interest and penalties for the years ended December 31, 2025, 2024 and 2023, respectively. We had $4,071 and $3,558 accrued for the payment of interest and penalties as of December 31, 2025 and 2024, respectively.

A summary of tax years that remain subject to examination by major tax jurisdictions is as follows:

The normal statute of limitations for United States federal tax purposes is three years from the date the tax return is filed; however, the statute of limitations may remain open for periods longer than three years in instances where a federal tax examination is in progress. The 2025, 2024 and 2023 tax years and net operating loss carryforwards utilized in these years remain subject to examination for United States federal tax purposes. The normal statute of limitations for state purposes is between three to five years. However, certain of our state statute of limitations remain open for periods longer than this when audits are in progress.

We are subject to income taxes in the United States and numerous foreign jurisdictions. We are subject to examination by various tax authorities in jurisdictions in which we have business operations or a taxable presence. We regularly assess the likelihood of additional assessments by tax authorities and provide for these matters as appropriate. As of December 31, 2025, we had $28,478 of reserves related to uncertain tax positions, of which $25,020 and $3,458 is included in Other Long-term Liabilities and Deferred Income Taxes, respectively, in the accompanying Consolidated Balance Sheet. As of December 31, 2024, we had $25,876 of reserves related to uncertain tax positions, of which $19,740 and $6,136 is included in Other Long-term Liabilities and Deferred Income Taxes, respectively, in the accompanying Consolidated Balance Sheet. Although we believe our tax estimates are appropriate, the final determination of tax audits and any related litigation could result in changes to our estimates.

Part IV

A rollforward of unrecognized tax benefits is as follows:

INCOME TAX PAYMENTS

Pursuant to the disclosure requirements of ASU 2023-09, the following is a summary of income taxes paid by jurisdiction for the year ended December 31, 2025:

Part IV

10. SEGMENT INFORMATION

Our Chief Operating Decision Maker (“CODM”), our President and CEO, uses Adjusted EBITDA as the basis for evaluating the performance of, and allocating resources to, our operating segments. The CODM uses Adjusted EBITDA to ensure that resources, including capital, are allocated strategically to support our strategy.

As of December 31, 2025, ourtwo reportable segments are described as follows:

(1)Global Records and Information Management ("Global RIM") Business includes several distinct offerings:

(i)Records Management, which stores physical records and provides information services, vital records services, courier operations, and the collection, handling and disposal of sensitive documents ("Records Management") for customers in 61 countries around the globe.

(ii)Data Management, which provides storage and rotation of backup computer media as part of corporate disaster recovery plans, including service and courier operations, server and computer backup services and related services offerings ("Data Management").

(iii)Global Digital Solutions, which develops, implements and supports comprehensive storage and information management solutions for the complete lifecycle of our customers’ information, including the management of physical records, conversion of documents to digital formats and digital storage of information. In October 2025, we launched version 2.0 of our Digital Experience Platform (also referred to as DXP), which offers enhanced content management and smart document processing, an easy-to-use secure platform with workflow tools and Artificial Intelligence agents, allowing customers to make faster and more insightful decisions as well as eliminate obsolete and duplicative data to save costs.

(iv)Secure Shredding, which includes the scheduled pick-up of office records that customers accumulate in specially designed secure containers we provide and is a natural extension of our hardcopy records management operations, completing the lifecycle of a record. Through a combination of shredding facilities and mobile shredding units consisting of custom built trucks, we are able to offer secure shredding services to our customers.

(v)Media and Archive Services, which includes entertainment and media services, which help industry clients store, safeguard and deliver physical media of all types, and provides digital content repository systems that house, distribute and archive key media assets.

(vi)Consumer Storage, which provides on-demand, valet storage for consumers utilizing data analytics and machine learning to provide effective customer acquisition and a convenient and seamless consumer storage experience.

(2)Global Data Center Business, which provides enterprise-class data center facilities and hyperscale-ready capacity to protect mission-critical assets and ensure the continued operation of our customers’ IT infrastructure, with secure, reliable and flexible data center options.

The remaining activities of our business consist primarily of our ALM and Fine Arts businesses and Corporate and Other.

(i)ALM provides hyperscale and corporate IT infrastructure managers with services and solutions that enable the decommissioning, data erasure, processing and disposition, and recycling or sale of IT hardware and component assets. ALM services are enabled by: secure logistics, chain of custody and complete asset traceability practices, environmentally-responsible asset processing and recycling, and data sanitization and asset refurbishment services that enable value recovery through asset remarketing. In addition, ALM also offers workplace IT asset management services including storage, configuration, deployment, device support, end-of-life disposition and recycling or sale of employee IT devices. Our ALM services focus on protecting and eradicating customer data while maintaining strong, auditable and transparent chain of custody practices.

(ii)Fine Arts provides technical expertise in the handling, installation and storing of art.

(iii)Corporate and Other also includes costs related to executive and staff functions, including finance, human resources and IT, which benefit the enterprise as a whole.

Part IV

The accounting policies of our reportable segments are the same as those described in Note 2.

The operations associated with acquisitions completed during 2025 have been incorporated into our Global RIM Business and Corporate and Other.

An analysis of our business segment information and reconciliation to the accompanying Consolidated Financial Statements is as follows:

(1)Relates to Cost of sales (excluding depreciation and amortization) and Selling, general and administrative expenses for the respective reportable segment. The CODM does not regularly review disaggregated expense information included within “Other Segment Items” for any individual segments but may review consolidated Cost of sales (excluding depreciation and amortization) and consolidated Selling, general and administrative expense information to manage the business.

(2)Excludes all intercompany receivables or payables and investment in subsidiary balances.

Part IV

A reconciliation of Adjusted EBITDA for our reportable segments to total Net Income (Loss) Before Provision (Benefit) for Income Taxes for the years ended December 31, 2025, 2024 and 2023 is as follows:

Part IV

Information as to our operations in different geographical areas for the years ended December 31, 2025, 2024 and 2023 is as follows:

Information as to our revenues by product and service lines by segment for the years ended December 31, 2025, 2024 and 2023 is as follows:

(1)Each of these offerings has a component of revenue that is storage rental related and a component that is service related, except for information destruction, which does not have a storage rental component.

(2)Information destruction revenue for our Global RIM Business includes secure shredding services.

(3)Information destruction revenue for Corporate and Other includes product revenue from our ALM business.

Part IV

11. RELATED PARTY TRANSACTIONS

In October 2020, in connection with the formation of the Frankfurt JV, we entered into agreements whereby we earn various fees, including (i) special project revenue and (ii) property management and construction and development fees for services we are providing to the Frankfurt JV (the "Frankfurt JV Agreements").

Revenue recognized in the accompanying Consolidated Statements of Operations under these agreements for the years ended December 31, 2025, 2024 and 2023 is as follows (approximately):

(1)Revenue associated with the Frankfurt JV Agreements is presented as a component of our Global Data Center Business segment.

(2)Relates to revenue associated with certain storage and related services provided to the Clutter JV (the "Clutter Agreement"), which were presented as a component of our Global RIM Business segment through June 2023. In June 2023, we acquired a controlling interest in the Clutter JV and terminated the Clutter Agreement.

12. RESTRUCTURING AND OTHER TRANSFORMATION

In 2025, we completed our investments in Project Matterhorn, a global program designed to accelerate the growth of our business, which we announced in September 2022. Project Matterhorn investments focused on transforming our operating model to a global operating model. Project Matterhorn enabled the development of a solution-based sales approach that allowed us to optimize our shared services and best practices to better serve our customers' needs. As part of this, we invested to accelerate growth and to capture a greater share of the large, global addressable markets in which we operate. We incurred approximately $574,400 in Restructuring and other transformation costs related to Project Matterhorn since its inception. Costs were comprised of (1) restructuring costs, which included (i) site consolidation and other related exit costs, (ii) employee severance costs and (iii) certain professional fees associated with these activities, and (2) other transformation costs, which included professional fees such as project management costs and costs for third party consultants who assisted in the enablement of our growth initiatives.

Restructuring and other transformation related to Project Matterhorn included in the accompanying Consolidated Statements of Operations for the years ended December 31, 2025, 2024 and 2023 and from the inception of Project Matterhorn through December 31, 2025 is as follows:

Part IV

12. RESTRUCTURING AND OTHER TRANSFORMATION (CONTINUED)

Restructuring costs for Project Matterhorn, included as a component of Restructuring and other transformation in the accompanying Consolidated Statements of Operations, by segment, for the years ended December 31, 2025, 2024 and 2023 and from the inception of Project Matterhorn through December 31, 2025 are as follows:

Other transformation costs for Project Matterhorn, included as a component of Restructuring and other transformation in the accompanying Consolidated Statements of Operations, by segment, for the years ended December 31, 2025, 2024 and 2023 and from the inception of Project Matterhorn through December 31, 2025 are as follows:

A rollforward of the accrued restructuring costs and accrued other transformation costs, which are included as components of Accrued expenses and other current liabilities in our Consolidated Balance Sheets for December 31, 2023 through December 31, 2025 is as follows: