Supplemental Financial Information Second Quarter 2025 investors.ironmountain.com

Table of Contents Section I - Q2 Earnings Press Release Q2 2025 Earnings Press Release 3 Section II - Financial Highlights and Organic Growth Financial and Operating Highlights 6 Organic Revenue Growth 7 Section III - Operational Metrics Global Storage Volume 8 Quarterly Operating Performance 9 Year to Date Operating Performance 10 Section IV - Balance Sheets, Statements of Operations and Reconciliations Condensed Consolidated Balance Sheets 11 Quarterly Condensed Consolidated Statements of Operations 12 Year to Date Condensed Consolidated Statements of Operations 13 Quarterly and Year to Date Reconciliation of Net (Loss) Income to Adjusted EBITDA 14 Quarterly and Year to Date Reconciliation of Reported Earnings per Share to Adjusted Earnings per Share 15 Quarterly Reconciliation of Net (Loss) Income to FFO and AFFO 16 Year to Date Reconciliation of Net (Loss) Income to FFO and AFFO 17 Section V - Storage and Service Reconciliation Quarterly Storage Rental and Service Business Detail 18 Year to Date Storage and Service Business Detail 19 Section VI - Real Estate Metrics Global Real Estate Portfolio and Lease Obligations 20 Facility Lease Expirations 20 Section VII - Data Center Customer and Portfolio Metrics Data Center Customer Lease Expiration and Leasing Activity Summary 21 Data Center Operating Portfolio and Total Potential Capacity 22 Data Center Expansion and Development Activity 23 Section VIII - Capitalization and Debt Maturity Profile Capitalization 24 Total Borrowings Maturity Schedule 24 Debt Maturity Profile 24 Section IX - Capital Expenditures Quarterly Capital Expenditures and Investments 25 Year to Date Capital Expenditures and Investments 25 Section X - Appendix and Definitions Appendix and Definitions 26 All figures except per share, megawatts (MW), kilowatts (kW), and facility counts in 000s unless noted All figures in reported dollars unless noted Figures may not foot due to rounding All figures for the quarter ended June 30, 2025 unless noted Unaudited investors.ironmountain.com Q2 2025 Supplemental Financial Information 2

FOR IMMEDIATE RELEASE Iron Mountain Reports Second Quarter 2025 Results • Achieves record quarterly revenue of $1.7 billion, an increase of 11.6% on a reported basis and an increase of 11.0% excluding the effects of foreign exchange • Data center, digital, and asset lifecycle management (ALM) businesses collectively grew more than 30% • The impact of changes in the exchange rates on intercompany balances led to a loss to Net Income of $43 million • Delivers record quarterly Adjusted EBITDA of $628 million • Generates record quarterly AFFO of $370 million, or $1.24 per share • Increases 2025 financial guidance driven by strong operational outperformance PORTSMOUTH, N.H. – August 6, 2025 – Iron Mountain Incorporated (NYSE: IRM), a global leader in information management services, announces financial results for the second quarter of 2025. “We are pleased to report outstanding performance in the second quarter, resulting in record financial performance across all key metrics and above our expectations. Our team’s successful execution of our strategy and commitment to delivering value for our customers, whilst leveraging our synergistic business model continues to drive industry leading growth and record results across each of our business segments,” said William L. Meaney, President and CEO of Iron Mountain. “The collective strength in our growth businesses and the sustained growth in our physical records storage business creates strong momentum which is expected to continue to deliver meaningful overall revenue and profit growth at these levels for the foreseeable future. Based on our strong Q2 outperformance and positive outlook, we are increasing our full year guidance.” Financial Performance Highlights for the Second Quarter of 2025 ($ in millions, except per share data) Three Months Ended Y/Y % Change Year to Date Y/Y % Change 6/30/25 6/30/24 Reported $ Constant Fx 6/30/25 6/30/24 Reported $ Constant Fx Storage Rental Revenue $1,010 $920 10% 9% $1,958 $1,805 9% 9% Service Revenue $702 $615 14% 14% $1,346 $1,207 12% 12% Total Revenues $1,712 $1,534 12% 11% $3,304 $3,011 10% 10% Net (Loss) Income $(43) $35 n/a $(27) $112 (124)% Reported EPS $(0.15) $0.12 n/a $(0.10) $0.37 (127)% Adjusted EPS $0.48 $0.42 14% $0.92 $0.85 8% Adjusted EBITDA $628 $544 15% 15% $1,208 $1,063 14% 14% Adjusted EBITDA Margin 36.7% 35.5% 120 bps 36.6% 35.3% 130 bps AFFO $370 $321 15% $718 $645 11% AFFO per share $1.24 $1.08 15% $2.41 $2.18 11% • Total reported revenues for the second quarter were $1.7 billion, compared with $1.5 billion in the second quarter of 2024, an increase of 11.6%. Excluding the impact of foreign currency exchange ("Fx"), total reported revenues increased 11.0% compared to the prior year, driven by a 9.2% increase in storage rental revenue and a 13.7% increase in service revenue. Year to date, total reported revenues increased 9.7%, or 10.2% excluding the impact of Fx. • Net (Loss) Income for the second quarter was $(43.3) million, compared with $34.6 million in the second quarter of 2024, driven by the impact of changes in the exchange rates on our intercompany balances. Year to date, Net (Loss) Income was $(27.1) million, compared with $111.6 million in 2024. • Adjusted EBITDA for the second quarter was $628.4 million, compared with $544.4 million in the second quarter of 2024, an increase of 15.4%. On a constant currency basis, Adjusted EBITDA increased by 15.1% in the second quarter, compared to the second quarter of 2024, Section I - Q2 Earnings Press Release investors.ironmountain.com Q2 2025 Supplemental Financial Information 3

driven by increased revenue in our Global RIM, ALM, and Data Center businesses and improved operating leverage coming from our continued improvement activities. Year to date, Adjusted EBITDA increased 13.6%, or 14.3% excluding the impact of Fx. • FFO (Normalized) per share was $0.87 for the second quarter, compared with $0.78 in the second quarter of 2024, an increase of 11.5%. Year to date, FFO (Normalized) per share was $1.64, compared with $1.53 in 2024, or an increase of 7.2%. • AFFO was $369.7 million for the second quarter, compared with $320.9 million in the second quarter of 2024, an increase of 15.2% driven by improved Adjusted EBITDA. Year to date, AFFO was $718.1 million compared with $644.6 million, or an increase of 11.4%. • AFFO per share was $1.24 for the second quarter, compared with $1.08 in the second quarter of 2024, an increase of 14.8%. Year to date, AFFO per share was $2.41, compared to $2.18 in 2024, or an increase of 10.6%. Dividend On August 6, 2025, Iron Mountain's Board of Directors declared a quarterly cash dividend of $0.785 per share of common stock for the third quarter. The third quarter 2025 dividend is payable on October 3, 2025, to shareholders of record at the close of business on September 15, 2025. Guidance Iron Mountain increased full year 2025 guidance; details are summarized in the table below. 2025 Guidance(1) ($ in millions, except per share data) New Approximate Y/Y % Change at Midpoint Previous Approximate Y/Y % Change at Midpoint Total Revenue $6,790 - $6,940 ~12% $6,740 - $6,890 ~11% Adjusted EBITDA $2,520 - $2,570 ~14% $2,505 - $2,555 ~13% AFFO $1,505 - $1,530 ~13% $1,480 - $1,510 ~11% AFFO Per Share $5.04 - $5.13 ~12% $4.95 - $5.05 ~10% (1) Iron Mountain does not provide a reconciliation of non-GAAP measures that it discusses as part of its annual guidance or long term outlook because certain significant information required for such reconciliation is not available without unreasonable efforts or at all, including, most notably, the impact of exchange rates on Iron Mountain’s transactions, loss or gain related to the disposition of real estate and other income or expense. Without this information, Iron Mountain does not believe that a reconciliation would be meaningful. Q2 2025 Earnings Conference Call and Related Materials The conference call / webcast details, earnings presentation and supplemental financial information, which includes definitions of certain capitalized terms used in this release, are available on Iron Mountain’s Investor Relations website. About Iron Mountain Iron Mountain Incorporated (NYSE: IRM) is 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 needs. Our longstanding commitment to safety, security, sustainability and innovation in support of our customers underpins everything we do. To learn more about Iron Mountain, please visit www.IronMountain.com. Investor Relations Contacts: Mark Rupe Erika Crabtree SVP, Investor Relations Manager, Investor Relations Mark.Rupe@ironmountain.com Erika.Crabtree@ironmountain.com (215) 402-7013 (617) 535-2845 Media Contact: media@ironmountain.com Section I - Q2 Earnings Press Release investors.ironmountain.com Q2 2025 Supplemental Financial Information 4

Safe Harbor Statement Under the Private Securities Litigation Reform Act of 1995: We have made statements in this press release that constitute "forward-looking statements" as that term is defined in the Private Securities Litigation Reform Act of 1995 and other securities laws. These forward-looking statements concern our current expectations regarding our future results from operations, economic performance, financial condition, goals, strategies, investment objectives, plans and achievements. These forward-looking statements are subject to various known and unknown risks, uncertainties and other factors, and you should not rely upon them except as statements of our present intentions and of our present expectations, which may or may not occur. When we use words such as “believes”, “expects”, “anticipates”, “estimates”, “plans”, “intends”, “projects”, “pursue”, “commits”, “will” or similar expressions, we are making forward-looking statements. Although we believe that our forward-looking statements are based on reasonable assumptions, our expected results may not be achieved, and actual results may differ materially from our expectations. In addition, important factors that could cause actual results to differ from expectations include, among others: (i) our ability or inability to execute our strategic growth plan, including our ability to invest according to plan, grow our businesses (including through joint ventures or other co-investment vehicles), incorporate alternative technologies (including artificial intelligence) into our offerings, achieve satisfactory returns on new product offerings, continue our revenue management, expand and manage our global operations, complete acquisitions on satisfactory terms, integrate acquired companies efficiently and transition to more sustainable sources of energy; (ii) changes in customer preferences and demand for our storage and information management services, including as a result of the shift from paper and tape storage to alternative technologies that require less physical space; (iii) the costs of complying with and our ability to comply with laws, regulations and customer requirements, including those relating to data privacy and cybersecurity issues, as well as fire and safety and environmental standards; (iv) the impact of attacks on our internal information technology (“IT”) systems, including the impact of such incidents on our reputation and ability to compete and any litigation or disputes that may arise in connection with such incidents; (v) our ability to fund capital expenditures; (vi) the impact of our distribution requirements on our ability to execute our business plan; (vii) our ability to remain qualified for taxation as a real estate investment trust for United States federal income tax purposes; (viii) changes in the political and economic environments in the countries in which we operate and changes in the global political climate; (ix) our ability to raise debt or equity capital and changes in the cost of our debt; (x) our ability to comply with our existing debt obligations and restrictions in our debt instruments; (xi) the impact of service interruptions or equipment damage and the cost of power on our data center operations; (xii) the cost or potential liabilities associated with real estate necessary for our business; (xiii) unexpected events, including those resulting from climate change or geopolitical events, could disrupt our operations and adversely affect our reputation and results of operations; (xiv) failures to implement and manage new IT systems; (xv) other trends in competitive or economic conditions affecting our financial condition or results of operations not presently contemplated; and (xvi) the other risks described in our periodic reports filed with the SEC, including under the caption “Risk Factors” in Part I, Item 1A of our Annual Report. Except as required by law, we undertake no obligation to update any forward-looking statements appearing in this press release. Reconciliation of Non-GAAP Measures Throughout this press release, Iron Mountain discusses (1) Adjusted EBITDA, (2) Adjusted EPS, (3) FFO (Nareit), (4) FFO (Normalized), and (5) AFFO. These measures do not conform to accounting principles generally accepted in the United States (“GAAP”). These non-GAAP measures are supplemental metrics designed to enhance our disclosure and to provide additional information that we believe to be important for investors to consider in addition to, but not as a substitute for, other measures of financial performance reported in accordance with GAAP, such as operating income, net income (loss) attributable to Iron Mountain Incorporated or cash flows from operating activities (as determined in accordance with GAAP). The reconciliation of these measures to the appropriate GAAP measure, as required by Regulation G under the Securities Exchange Act of 1934, as amended, and their definitions are included later in this release. Section I - Q2 Earnings Press Release investors.ironmountain.com Q2 2025 Supplemental Financial Information 5

Financial Highlights Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Storage Rental Revenue $1,009,989 $948,376 $941,970 $935,701 $919,746 Service Revenue $701,959 $644,153 $639,309 $621,657 $614,663 Total Revenues $1,711,948 $1,592,529 $1,581,279 $1,557,358 $1,534,409 Adjusted EBITDA $628,388 $579,906 $605,051 $568,113 $544,361 Adjusted EBITDA Margin 36.7 % 36.4 % 38.3 % 36.5 % 35.5 % Net (Loss) Income Attributable to Iron Mountain Incorporated $(44,921) $15,952 $103,932 $(33,620) $35,783 Reported EPS - Fully Diluted $(0.15) $0.05 $0.35 $(0.11) $0.12 Adjusted EPS $0.48 $0.43 $0.50 $0.44 $0.42 FFO (Normalized) $258,005 $229,070 $252,468 $233,269 $231,021 FFO (Normalized) per Share $0.87 $0.77 $0.85 $0.79 $0.78 AFFO $369,744 $348,400 $367,986 $332,000 $320,901 AFFO per Share $1.24 $1.17 $1.24 $1.13 $1.08 TTM AFFO Payout Ratio 62.7 % 62.0 % 60.0 % 60.3 % 60.3 % Dividend per Share $0.79 $0.79 $0.72 $0.72 $0.65 Net Lease-Adjusted Leverage Ratio 5.0x 5.0x 5.0x 5.0x 5.0x Operating Highlights Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Organic Storage Rental Revenue Growth 9.2 % 8.8 % 8.8 % 9.3 % 10.1 % Organic Service Revenue Growth 9.7 % 7.1 % 7.0 % 10.0 % 9.4 % Total Volume - Storage 735,807 734,166 733,571 732,997 732,607 Storage Facility Capacity Utilization 80.6 % 79.9 % 79.6 % 79.4 % 79.2 % Records Management Retention Rate 93.0 % 92.9 % 92.6 % 92.7 % 92.8 % Storage Revenue / Sq. Ft. $10.83 $10.14 $10.07 $9.92 $9.74 Storage NOI / Sq. Ft. $8.69 $8.10 $8.14 $7.95 $7.75 Data Center: Leasable Megawatts 450.2 424.2 416.2 364.7 265.7 Leased % - Stabilized 97.9 % 98.0 % 97.4 % 98.7 % 96.0 % Leased % - Total 96.3 % 96.1 % 95.5 % 96.8 % 93.5 % Kilowatts Leased - New/Expansion 2,325 3,700 9,664 9,205 66,493 Churn 0.5 % 0.3 % 4.4 % 0.5 % 1.2 % Number of Facilities 30 29 29 28 26 Number of Markets 21 21 21 21 21 Section II - Financial Highlights and Organic Growth investors.ironmountain.com Q2 2025 Supplemental Financial Information 6

Organic Revenue Growth (1) Q2 2025 Q1 2025 YTD 2025 Reported Constant Currency Organic Revenue Reported Constant Currency Organic Revenue Reported Constant Currency Organic Revenue Storage Rental 9.8% 9.2% 9.2% 7.2% 8.8% 8.8% 8.5% 9.0% 9.0% Service 14.2% 13.7% 9.7% 8.8% 10.2% 7.1% 11.6% 12.0% 8.4% Total Revenues 11.6% 11.0% 9.4% 7.8% 9.4% 8.1% 9.7% 10.2% 8.8% Total Organic Revenue Growth 5.5% 8.7% 8.3% 9.8% 9.5% 8.1% 8.1% 9.4% Q3 2023 Q4 2023 Q1 2024 Q2 2024 Q3 2024 Q4 2024 Q1 2025 Q2 2025 0.0% 2.0% 4.0% 6.0% 8.0% 10.0% 12.0% Organic Storage Rental Revenue Growth 9.7% 10.4% 7.5% 10.1% 9.3% 8.8% 8.8% 9.2% Q3 2023 Q4 2023 Q1 2024 Q2 2024 Q3 2024 Q4 2024 Q1 2025 Q2 2025 6.0% 8.0% 10.0% 12.0% Organic Service Revenue Growth (.6)% 6.2% 9.6% 9.4% 10.0% 7.0% 7.1% 9.7% Q3 2023 Q4 2023 Q1 2024 Q2 2024 Q3 2024 Q4 2024 Q1 2025 Q2 2025 (4.0)% 0.0% 4.0% 8.0% 12.0% (1) Constant Currency and excluding impact from business acquisitions and divestitures. Section II - Financial Highlights and Organic Growth investors.ironmountain.com Q2 2025 Supplemental Financial Information 7

Global Storage Volume Global RIM Corporate and Other Q1 2023 Q2 2023 Q3 2023 Q4 2023 Q1 2024 Q2 2024 Q3 2024 Q4 2024 Q1 2025 Q2 2025 700,000 710,000 720,000 730,000 740,000 Q1 2023 Q2 2023 Q3 2023 Q4 2023 Q1 2024 Q2 2024 Q3 2024 Q4 2024 Q1 2025 Q2 2025 Global RIM 724,926 725,510 (1) 725,907 726,048 726,316 726,712 726,952 727,266 727,496 728,740 Corporate and Other 5,210 5,256 5,356 5,493 5,715 5,895 6,045 6,305 6,671 7,067 Total Volume - Storage 730,136 730,767 731,263 731,541 732,031 732,607 732,997 733,571 734,166 735,807 Business acquisitions during the quarter (2) — — — — — — — — — — (1) On June 29, 2023, we acquired 100% interest in Clutter Intermediate, Inc. and control of all assets of the related Clutter joint venture, of which we had a preexisting relationship. The volume associated with this business both prior and subsequent to our acquisition is substantially consistent. (2) Volume acquired through acquisition in the quarter; this is included in Total Storage Volume. Section III - Operational Metrics investors.ironmountain.com Q2 2025 Supplemental Financial Information 8

Quarterly Operating Performance Y/Y % Change Q2 2025 Q1 2025 Q2 2024 Reported Constant Currency Organic Growth (1) Global RIM Business Storage Rental $803,580 $757,508 $756,358 6.2% 5.8% 5.8% Service 520,218 498,434 494,219 5.3% 4.9% 4.9% Total Revenues $1,323,798 $1,255,942 $1,250,577 5.9% 5.4% 5.4% Adjusted EBITDA $586,303 $556,314 $548,742 Adjusted EBITDA Margin 44.3 % 44.3 % 43.9 % Global Data Center Business Storage Rental $188,279 $172,945 $147,397 27.7% 26.1% 26.1% Service 1,122 252 5,305 (78.9)% (79.7)% (79.7)% Total Revenues $189,401 $173,197 $152,702 24.0% 22.4% 22.4% Adjusted EBITDA $96,266 $90,816 $66,017 Adjusted EBITDA Margin 50.8 % 52.4 % 43.2 % Corporate and Other Storage Rental $18,130 $17,923 $15,991 13.4% 12.2% 12.2% Service 180,619 145,467 115,139 56.9% 56.3% 34.5% Total Revenues $198,749 $163,390 $131,130 51.6% 50.9% 31.8% Adjusted EBITDA $(54,181) $(67,224) $(70,398) Total Consolidated Storage Rental $1,009,989 $948,376 $919,746 9.8% 9.2% 9.2% Service 701,959 644,153 614,663 14.2% 13.7% 9.7% Total Revenues $1,711,948 $1,592,529 $1,534,409 11.6% 11.0% 9.4% Adjusted EBITDA $628,388 $579,906 $544,361 Adjusted EBITDA Margin 36.7 % 36.4 % 35.5 % (1) Constant Currency and excluding impact from business acquisitions and divestitures. Section III - Operational Metrics investors.ironmountain.com Q2 2025 Supplemental Financial Information 9

Year to Date Operating Performance Y/Y % Change YTD 2025 YTD 2024 Reported Constant Currency Organic Growth (1) Global RIM Business Storage Rental $1,561,088 $1,485,342 5.1% 5.7% 5.7% Service 1,018,652 975,392 4.4% 5.0% 5.0% Total Revenues $2,579,740 $2,460,734 4.8% 5.4% 5.4% Adjusted EBITDA $1,142,617 $1,075,010 Adjusted EBITDA Margin 44.3 % 43.7 % Global Data Center Business Storage Rental $361,224 $287,425 25.7% 25.3% 25.3% Service 1,374 9,214 (85.1)% (85.4)% (85.4)% Total Revenues $362,598 $296,639 22.2% 21.8% 21.8% Adjusted EBITDA $187,082 $127,585 Adjusted EBITDA Margin 51.6 % 43.0 % Corporate and Other Storage Rental $36,053 $31,821 13.3% 12.8% 12.8% Service 326,086 222,078 46.8% 46.9% 27.3% Total Revenues $362,139 $253,899 42.6% 42.6% 25.5% Adjusted EBITDA $(121,405) $(139,379) Total Consolidated Storage Rental $1,958,365 $1,804,588 8.5% 9.0% 9.0% Service 1,346,112 1,206,684 11.6% 12.0% 8.4% Total Revenues $3,304,477 $3,011,272 9.7% 10.2% 8.8% Adjusted EBITDA $1,208,294 $1,063,216 Adjusted EBITDA Margin 36.6 % 35.3 % (1) Constant Currency and excluding impact from business acquisitions and divestitures. Section III - Operational Metrics investors.ironmountain.com Q2 2025 Supplemental Financial Information 10

Condensed Consolidated Balance Sheets 6/30/2025 12/31/2024 ASSETS Current Assets: Cash and Cash Equivalents $217,992 $155,716 Accounts Receivable, Net 1,387,110 1,291,379 Prepaid Expenses and Other 292,146 244,127 Total Current Assets $1,897,248 $1,691,222 Property, Plant and Equipment: Property, Plant and Equipment $13,500,719 $11,985,997 Less: Accumulated Depreciation (4,725,996) (4,354,398) Property, Plant and Equipment, Net $8,774,723 $7,631,599 Other Assets, Net: Goodwill $5,229,943 $5,083,817 Customer and Supplier Relationships and Other Intangible Assets 1,244,957 1,274,731 Operating Lease Right-of-Use Assets 2,414,510 2,489,893 Other 615,408 545,853 Total Other Assets, Net $9,504,818 $9,394,294 Total Assets $20,176,789 $18,717,115 LIABILITIES AND EQUITY Current Liabilities: Current Portion of Long-term Debt $777,881 $715,109 Accounts Payable 650,906 678,716 Accrued Expenses and Other Current Liabilities 1,227,760 1,366,568 Deferred Revenue 342,225 326,882 Total Current Liabilities $2,998,772 $3,087,275 Long-term Debt, Net of Current Portion 14,818,175 13,003,977 Long-term Operating Lease Liabilities, Net of Current Portion 2,254,841 2,334,826 Other Long-term Liabilities 375,971 312,199 Deferred Income Taxes 221,045 205,341 Redeemable Noncontrolling Interests 76,852 78,171 Total Long-term Liabilities $17,746,884 $15,934,514 Total Liabilities $20,745,656 $19,021,789 (Deficit) Equity Total (Deficit) Equity $(568,867) $(304,674) Total Liabilities and (Deficit) Equity $20,176,789 $18,717,115 Section IV - Balance Sheets, Statements of Operations and Reconciliations investors.ironmountain.com Q2 2025 Supplemental Financial Information 11

Quarterly Condensed Consolidated Statements of Operations Q2 2025 Q1 2025 Q/Q % Change Q2 2024 Y/Y % Change Revenues: Storage Rental $1,009,989 $948,376 6.5 % $919,746 9.8 % Service 701,959 644,153 9.0 % 614,663 14.2 % Total Revenues $1,711,948 $1,592,529 7.5 % $1,534,409 11.6 % Operating Expenses: Cost of Sales (excluding Depreciation and Amortization) $754,837 $710,204 6.3 % $675,971 11.7 % Selling, General and Administrative 390,456 329,737 18.4 % 344,838 13.2 % Depreciation and Amortization 252,566 232,154 8.8 % 224,501 12.5 % Acquisition and Integration Costs 4,815 5,823 (17.3) % 9,502 (49.3) % Restructuring and Other Transformation 50,340 54,746 (8.0) % 46,513 8.2 % (Gain) Loss on Disposal/Write-Down of PP&E, Net (962) 5,571 (117.3) % 2,790 (134.5) % Total Operating Expenses $1,452,052 $1,338,235 8.5 % $1,304,115 11.3 % Operating Income (Loss) $259,896 $254,294 2.2 % $230,294 12.9 % Interest Expense, Net 205,063 194,738 5.3 % 176,521 16.2 % Other Expense (Income), Net 81,877 28,488 187.4 % 5,833 n/a Net (Loss) Income Before Provision (Benefit) for Income Taxes $(27,044) $31,068 (187.0) % $47,940 (156.4) % Provision (Benefit) for Income Taxes 16,296 14,835 9.8 % 13,319 22.4 % Net (Loss) Income $(43,340) $16,233 n/a $34,621 n/a Less: Net Income (Loss) Attributable to Noncontrolling Interests 1,581 281 n/a (1,162) n/a Net (Loss) Income Attributable to Iron Mountain Incorporated $(44,921) $15,952 n/a $35,783 n/a Net (Loss) Income Per Share Attributable to Iron Mountain Incorporated: Basic $(0.15) $0.05 n/a $0.12 n/a Diluted $(0.15) $0.05 n/a $0.12 n/a Weighted Average Common Shares Outstanding - Basic 295,364 294,507 0.3 % 293,340 0.7 % Weighted Average Common Shares Outstanding - Diluted 295,364 297,260 (0.6) % 295,838 (0.2) % Section IV - Balance Sheets, Statements of Operations and Reconciliations investors.ironmountain.com Q2 2025 Supplemental Financial Information 12

Year to Date Condensed Consolidated Statements of Operations YTD 2025 YTD 2024 % Change Revenues: Storage Rental $1,958,365 $1,804,588 8.5 % Service 1,346,112 1,206,684 11.6 % Total Revenues $3,304,477 $3,011,272 9.7 % Operating Expenses: Cost of Sales (excluding Depreciation and Amortization) $1,465,041 $1,329,226 10.2 % Selling, General and Administrative 720,193 664,303 8.4 % Depreciation and Amortization 484,720 434,056 11.7 % Acquisition and Integration Costs 10,638 17,311 (38.5) % Restructuring and Other Transformation 105,086 87,280 20.4 % Loss (Gain) on Disposal/Write-Down of PP&E, Net 4,609 3,179 45.0 % Total Operating Expenses $2,790,287 $2,535,355 10.1 % Operating Income (Loss) $514,190 $475,917 8.0 % Interest Expense, Net 399,801 341,040 17.2 % Other Expense (Income), Net 110,365 (6,697) n/a Net Income (Loss) Before Provision (Benefit) for Income Taxes $4,024 $141,574 (97.2) % Provision (Benefit) for Income Taxes 31,131 29,928 4.0 % Net (Loss) Income $(27,107) $111,646 (124.3) % Less: Net Income (Loss) Attributable to Noncontrolling Interests 1,862 1,802 3.3 % Net (Loss) Income Attributable to Iron Mountain Incorporated $(28,969) $109,844 (126.4) % Net (Loss) Income Per Share Attributable to Iron Mountain Incorporated: Basic $(0.10) $0.37 (127.0) % Diluted $(0.10) $0.37 (127.0) % Weighted Average Common Shares Outstanding - Basic 294,935 293,043 0.6 % Weighted Average Common Shares Outstanding - Diluted 294,935 295,529 (0.2) % Section IV - Balance Sheets, Statements of Operations and Reconciliations investors.ironmountain.com Q2 2025 Supplemental Financial Information 13

Quarterly Reconciliation of Net (Loss) Income to Adjusted EBITDA Q2 2025 Q1 2025 Q/Q % Change Q2 2024 Y/Y % Change Net (Loss) Income $(43,340) $16,233 n/a $34,621 n/a Add / (Deduct): Interest Expense, Net 205,063 194,738 5.3 % 176,521 16.2 % Provision (Benefit) for Income Taxes 16,296 14,835 9.8 % 13,319 22.4 % Depreciation and Amortization 252,566 232,154 8.8 % 224,501 12.5 % Acquisition and Integration Costs 4,815 5,823 (17.3) % 9,502 (49.3) % Restructuring and Other Transformation 50,340 54,746 (8.0) % 46,513 8.2 % (Gain) Loss on Disposal/Write-Down of PP&E, Net (Including Real Estate) (962) 5,571 (117.3) % 2,790 (134.5) % Other Expense (Income), Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures 80,698 27,382 194.7 % 4,532 n/a Stock-Based Compensation Expense 60,354 26,094 131.3 % 29,889 101.9 % Our Share of Adjusted EBITDA Reconciling Items from our Unconsolidated Joint Ventures 2,558 2,330 9.8 % 2,173 17.7 % Adjusted EBITDA $628,388 $579,906 8.4 % $544,361 15.4 % Year to Date Reconciliation of Net (Loss) Income to Adjusted EBITDA YTD 2025 YTD 2024 % Change Net (Loss) Income $(27,107) $111,646 (124.3) % Add / (Deduct): Interest Expense, Net 399,801 341,040 17.2 % Provision (Benefit) for Income Taxes 31,131 29,928 4.0 % Depreciation and Amortization 484,720 434,056 11.7 % Acquisition and Integration Costs 10,638 17,311 (38.5) % Restructuring and Other Transformation 105,086 87,280 20.4 % Loss (Gain) on Disposal/Write-Down of PP&E, Net (Including Real Estate) 4,609 3,179 45.0 % Other Expense (Income), Net, Excluding our Share of (Losses) Gains from our Unconsolidated Joint Ventures 108,080 (8,578) n/a Stock-Based Compensation Expense 86,448 43,928 96.8 % Our Share of Adjusted EBITDA Reconciling Items from our Unconsolidated Joint Ventures 4,888 3,426 42.7 % Adjusted EBITDA $1,208,294 $1,063,216 13.6 % Section IV - Balance Sheets, Statements of Operations and Reconciliations investors.ironmountain.com Q2 2025 Supplemental Financial Information 14

Quarterly Reconciliation of Reported Earnings per Share to Adjusted Earnings per Share Q2 2025 Q1 2025 Q/Q % Change Q2 2024 Y/Y % Change Reported EPS - Fully Diluted from Net (Loss) Income Attributable to Iron Mountain Incorporated $(0.15) $0.05 n/a $0.12 n/a Add / (Deduct): Acquisition and Integration Costs 0.02 0.02 — 0.03 (33.3) % Restructuring and Other Transformation 0.17 0.18 (5.6) % 0.16 6.3 % Loss (Gain) on Disposal/Write-Down of PP&E, Net — 0.02 n/a 0.01 n/a Other Expense (Income), Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures 0.27 0.09 n/a 0.02 n/a Stock-Based Compensation Expense 0.20 0.09 122.2 % 0.10 100.0 % Non-Cash Amortization Related to Derivative Instruments 0.01 0.01 — 0.01 — Tax Impact of Reconciling Items and Discrete Tax Items (1) (0.04) (0.04) — (0.03) 33.3 % Income (Loss) Attributable to Noncontrolling Interests 0.01 — n/a — n/a Impact of Weighted Average Dilutive Shares (2) — — n/a — n/a Adjusted EPS - Fully Diluted from Net (Loss) Income Attributable to Iron Mountain Incorporated $0.48 $0.43 11.6 % $0.42 14.3 % Year to Date Reconciliation of Reported Earnings per Share to Adjusted Earnings per Share YTD 2025 YTD 2024 % Change Reported EPS - Fully Diluted from Net (Loss) Income Attributable to Iron Mountain Incorporated $(0.10) $0.37 (127.0) % Add / (Deduct): Acquisition and Integration Costs 0.04 0.06 (33.3) % Restructuring and Other Transformation 0.36 0.30 20.0 % Loss (Gain) on Disposal/Write-Down of PP&E, Net 0.02 0.01 100.0 % Other Expense (Income), Net, Excluding our Share of (Gains) Losses from our Unconsolidated Joint Ventures 0.37 (0.03) n/a Stock-Based Compensation Expense 0.29 0.15 93.3 % Non-Cash Amortization Related to Derivative Instruments 0.03 0.03 — Tax Impact of Reconciling Items and Discrete Tax Items (1) (0.08) (0.04) 100.0 % Income (Loss) Attributable to Noncontrolling Interests 0.01 0.01 — Impact of Weighted Average Dilutive Shares (2) (0.01) — n/a Adjusted EPS - Fully Diluted from Net (Loss) Income Attributable to Iron Mountain Incorporated $0.92 $0.85 8.2 % (1) The difference between our effective tax rates and our structural tax rate (or adjusted effective tax rates) for the three months ended June 30, 2025, June 30, 2024 and March 31, 2025 is primarily due to (i) the reconciling items above, which impact our reported net (loss) income before provision (benefit) for income taxes but have an insignificant impact on our reported provision (benefit) for income taxes and (ii) other discrete tax items. Our structural tax rate for purposes of the calculation of Adjusted EPS for the three and six months ended June 30, 2025 and 2024 was 16.7% and 14.5%, respectively, and three months ended March 31, 2025 was 17.0%. The Tax Impact of Reconciling Items and Discrete Tax Items was calculated using the current quarter’s estimate of the annual structural tax rate. This may result in the current period adjustment plus prior reported quarterly adjustments not summing to the full year adjustment. (2) Reflects the impact of dilutive shares of 2,278 and 2,516 for the three and six months ended June 30, 2025, respectively, not included in reported EPS-Fully Diluted due to our net loss position during the periods. Section IV - Balance Sheets, Statements of Operations and Reconciliations investors.ironmountain.com Q2 2025 Supplemental Financial Information 15

Quarterly Reconciliation of Net (Loss) Income to FFO and AFFO Q2 2025 Q1 2025 Q/Q % Change Q2 2024 Y/Y % Change Net (Loss) Income $(43,340) $16,233 n/a $34,621 n/a Add / (Deduct): Real Estate Depreciation (1) 107,186 94,147 13.8 % 97,771 9.6 % (Gain) Loss on Sale of Real Estate, Net of Tax (4,981) 312 n/a 579 n/a Data Center Lease-Based Intangible Assets Amortization (2) 1,683 2,019 (16.6) % 5,571 (69.8) % Our Share of FFO (Nareit) Reconciling Items from our Unconsolidated Joint Ventures 1,567 1,496 4.7 % 1,112 40.9 % FFO (Nareit) $62,115 $114,207 (45.6) % $139,654 (55.5) % Add / (Deduct): Acquisition and Integration Costs 4,815 5,823 (17.3) % 9,502 (49.3) % Restructuring and Other Transformation 50,340 54,746 (8.0) % 46,513 8.2 % Loss (Gain) on Disposal/Write-Down of PP&E, Net (Excluding Real Estate) 3,809 5,292 (28.0) % 2,211 72.3 % Other Expense (Income), Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures 80,698 27,382 194.7 % 4,532 n/a Stock-Based Compensation Expense 60,354 26,094 131.3 % 29,889 101.9 % Non-Cash Amortization Related to Derivative Instruments 4,177 4,176 — 4,177 — Real Estate Financing Lease Depreciation 3,426 3,148 8.8 % 3,236 5.9 % Tax Impact of Reconciling Items and Discrete Tax Items (3) (11,671) (11,673) — (8,643) 35.0 % Our Share of FFO (Normalized) Reconciling Items from our Unconsolidated Joint Ventures (58) (125) (53.6) % (50) 16.0 % FFO (Normalized) $258,005 $229,070 12.6 % $231,021 11.7 % Add / (Deduct): Non-Real Estate Depreciation 69,960 65,146 7.4 % 57,923 20.8 % Amortization Expense (4) 70,311 67,694 3.9 % 60,001 17.2 % Amortization of Deferred Financing Costs 7,803 7,856 (0.7) % 6,143 27.0 % Revenue Reduction Associated with Amortization of Customer Inducements and Above- and Below-Market Leases 1,659 1,317 26.0 % 1,475 12.5 % Non-Cash Rent Expense (Income) 783 3,225 (75.7) % 3,658 (78.6) % Reconciliation to Normalized Cash Taxes (4,172) 1,999 n/a (2,524) 65.3 % Our Share of AFFO Reconciling Items from our Unconsolidated Joint Ventures 189 176 7.4 % 180 5.0 % Less: Recurring Capital Expenditures 34,794 28,083 23.9 % 36,976 (5.9) % AFFO $369,744 $348,400 6.1 % $320,901 15.2 % Per Share Amounts (Fully Diluted Shares): FFO (Nareit) $0.21 $0.38 (44.7) % $0.47 (55.3) % FFO (Normalized) $0.87 $0.77 13.0 % $0.78 11.5 % AFFO Per Share $1.24 $1.17 6.0 % $1.08 14.8 % Weighted Average Common Shares Outstanding - Basic 295,364 294,507 0.3 % 293,340 0.7 % Weighted Average Common Shares Outstanding - Diluted (5) 297,642 297,260 0.1 % 295,838 0.6 % (1) Includes depreciation expense related to owned real estate assets (land improvements, buildings, building and leasehold improvements, data center infrastructure and racking structures), excluding depreciation related to real estate financing leases. (2) Includes amortization expense for Data Center In-Place Lease Intangible Assets and Data Center Tenant Relationship Intangible Assets. (3) Represents the tax impact of (i) the reconciling items above, which impacts our reported net (loss) income before provision (benefit) for income taxes but have an insignificant impact on our reported provision (benefit) for income taxes and (ii) other discrete tax items. (4) Includes customer and supplier relationship value, intake costs, acquisition of customer relationships, capitalized commissions and other intangibles. (5) Reflects the impact of dilutive shares of 2,278 for the three months ended June 30, 2025, not included in reported EPS-Fully Diluted due to our net loss position during the period. Section IV - Balance Sheets, Statements of Operations and Reconciliations investors.ironmountain.com Q2 2025 Supplemental Financial Information 16

Year to Date Reconciliation of Net (Loss) Income to FFO and AFFO YTD 2025 YTD 2024 % Change Net (Loss) Income $(27,107) $111,646 (124.3) % Add / (Deduct): Real Estate Depreciation (1) 201,333 181,344 11.0 % (Gain) Loss on Sale of Real Estate, Net of Tax (4,669) (615) n/a Data Center Lease-Based Intangible Assets Amortization (2) 3,702 11,147 (66.8) % Our Share of FFO (Nareit) Reconciling Items from our Unconsolidated Joint Ventures 3,063 1,553 97.2 % FFO (Nareit) $176,322 $305,075 (42.2) % Add / (Deduct): Acquisition and Integration Costs 10,638 17,311 (38.5) % Restructuring and Other Transformation 105,086 87,280 20.4 % Loss (Gain) on Disposal/Write-Down of PP&E, Net (Excluding Real Estate) 9,101 4,029 125.9 % Other Expense (Income), Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures 108,080 (8,578) n/a Stock-Based Compensation Expense 86,448 43,928 96.8 % Non-Cash Amortization Related to Derivative Instruments 8,353 8,353 — Real Estate Financing Lease Depreciation 6,574 6,222 5.7 % Tax Impact of Reconciling Items and Discrete Tax Items (3) (23,344) (12,813) 82.2 % Our Share of FFO (Normalized) Reconciling Items from our Unconsolidated Joint Ventures (183) (9) n/a FFO (Normalized) $487,075 $450,798 8.0 % Add / (Deduct): Non-Real Estate Depreciation 135,106 114,996 17.5 % Amortization Expense (4) 138,005 120,347 14.7 % Amortization of Deferred Financing Costs 15,659 12,243 27.9 % Revenue Reduction Associated with Amortization of Customer Inducements and Above- and Below-Market Leases 2,976 2,797 6.4 % Non-Cash Rent Expense (Income) 4,008 9,317 (57.0) % Reconciliation to Normalized Cash Taxes (2,173) (593) n/a Our Share of AFFO Reconciling Items from our Unconsolidated Joint Ventures 365 362 0.8 % Less: Recurring Capital Expenditures 62,877 65,713 (4.3) % AFFO $718,144 $644,554 11.4 % Per Share Amounts (Fully Diluted Shares): FFO (Nareit) $0.59 $1.03 (42.7) % FFO (Normalized) $1.64 $1.53 7.2 % AFFO Per Share $2.41 $2.18 10.6 % Weighted Average Common Shares Outstanding - Basic 294,935 293,043 0.6 % Weighted Average Common Shares Outstanding - Diluted (5) 297,451 295,529 0.7 % (1) Includes depreciation expense related to owned real estate assets (land improvements, buildings, building and leasehold improvements, data center infrastructure and racking structures), excluding depreciation related to real estate financing leases. (2) Includes amortization expense for Data Center In-Place Lease Intangible Assets and Data Center Tenant Relationship Intangible Assets. (3) Represents the tax impact of (i) the reconciling items above, which impact our reported net income (loss) before provision (benefit) for income taxes but have an insignificant impact on our reported provision (benefit) from income taxes and (ii) other discrete tax items. (4) Includes customer and supplier relationship value, intake costs, acquisition of customer relationships, capitalized commissions and other intangibles. (5) Reflects the impact of dilutive shares of 2,516 for the six months ended June 30, 2025, not included in reported EPS-Fully Diluted due to our net loss position during the period. Section IV - Balance Sheets, Statements of Operations and Reconciliations investors.ironmountain.com Q2 2025 Supplemental Financial Information 17

Quarterly Storage Rental and Service Business Detail Q2 2025 Q1 2025 Q/Q % Change Q2 2024 Y/Y % Change Storage Rental Business Detail Total Storage Rental Revenue $1,009,989 $948,376 6.5 % $919,746 9.8 % Plus: Terminations/Permanent Withdrawal Fees 9,266 7,875 17.7 % 10,562 (12.3) % Total Revenue from Adjusted Storage Rental Activities $1,019,255 $956,251 6.6 % $930,308 9.6 % Less: Storage Rental Expenses Storage Rent 125,397 121,506 3.2 % 121,657 3.1 % Storage Rental Labor 12,190 9,983 22.1 % 10,305 18.3 % All Other Storage Costs 153,708 149,478 2.8 % 147,385 4.3 % Storage Rental Cost of Sales $291,295 $280,966 3.7 % $279,346 4.3 % Storage Rental Gross Profit $727,960 $675,285 7.8 % $650,962 11.8 % Storage Rental Gross Margin 71.4 % 70.6 % 80 bps 70.0 % 140 bps Service Business Detail Total Service Revenue $701,959 $644,153 9.0 % $614,663 14.2 % Less: Terminations/Permanent Withdrawal Fees 9,266 7,875 17.7 % 10,562 (12.3) % Total Revenue from Adjusted Service Activities $692,693 $636,278 8.9 % $604,100 14.7 % Less: Service Expenses Service Rent 6,577 7,886 (16.6) % 6,863 (4.2) % Service Labor 280,153 263,998 6.1 % 253,863 10.4 % All Other Service Costs 176,812 157,353 12.4 % 135,898 30.1 % Service Cost of Sales $463,542 $429,238 8.0 % $396,625 16.9 % Service Gross Profit $229,151 $207,040 10.7 % $207,476 10.4 % Service Gross Margin 33.1 % 32.5 % 60 bps 34.3 % -120 bps Section V - Storage and Service Reconciliation investors.ironmountain.com Q2 2025 Supplemental Financial Information 18

Year to Date Storage Rental and Service Business Detail YTD 2025 YTD 2024 % Change Storage Rental Business Detail Total Storage Rental Revenue $1,958,365 $1,804,588 8.5 % Plus: Terminations/Permanent Withdrawal Fees 17,141 20,226 (15.3) % Total Revenue from Adjusted Storage Rental Activities $1,975,506 $1,824,814 8.3 % Less: Storage Rental Expenses Storage Rent 246,902 245,046 0.8 % Storage Rental Labor 22,173 20,565 7.8 % All Other Storage Costs 303,186 284,213 6.7 % Storage Rental Cost of Sales $572,261 $549,824 4.1 % Storage Rental Gross Profit $1,403,245 $1,274,990 10.1 % Storage Rental Gross Margin 71.0 % 69.9 % 110 bps Service Business Detail Total Service Revenue $1,346,112 $1,206,684 11.6 % Less: Terminations/Permanent Withdrawal Fees 17,141 20,226 (15.3) % Total Revenue from Adjusted Service Activities $1,328,971 $1,186,458 12.0 % Less: Service Expenses Service Rent 14,464 13,080 10.6 % Service Labor 544,151 494,934 9.9 % All Other Service Costs 334,165 271,389 23.1 % Service Cost of Sales $892,780 $779,402 14.5 % Service Gross Profit $436,191 $407,055 7.2 % Service Gross Margin 32.8 % 34.3 % -150 bps Section V - Storage and Service Reconciliation investors.ironmountain.com Q2 2025 Supplemental Financial Information 19

Global Real Estate Portfolio and Lease Obligations Global Real Estate Portfolio (1) Owned Facilities Leased Facilities Total Buildings Sq. Ft. Buildings Sq. Ft. Buildings Sq. Ft. Total as of 03/31/2025 237 24,216 1,103 73,687 1,340 97,902 Additions & Expansions 1 198 6 234 7 432 Dispositions & Move Outs (1) (55) (21) (467) (22) (522) Total as of 06/30/2025 (2) 237 24,358 1,088 73,453 1,325 97,811 Total % 17.9 % 24.9 % 82.1 % 75.1 % Top Five Markets Owned, United States (in Sq. Ft.) Top Five Markets Owned, International (in Sq. Ft.) Northern New Jersey 1,962 Paris, France 807 Chicago 1,282 Montreal, Canada 552 Boston 1,104 Mexico City, Mexico 452 Dallas 966 Toronto, Canada 434 Houston 873 Lima, Peru 434 Facility Lease Expirations (3) (% of total square feet subject to lease) 4.7% 6.5% 3.7% 4.9% 5.3% 4.0% 5.1% 3.6% 3.7% 58.5% 2025 2026 2027 2028 2029 2030 2031 2032 2033 Thereafter Weighted-Average Remaining Operating Lease Obligation: 10.2 Years (1) Includes real estate held in consolidated joint ventures. (2) Includes 16 owned data center facilities and 5 leased data center facilities with 3.7M Sq. Ft. and 0.8M Sq. Ft., respectively. (3) Includes financing and operating lease obligations. Section VI - Real Estate Metrics investors.ironmountain.com Q2 2025 Supplemental Financial Information 20

Data Center Customer Lease Expiration Year Number of Leases Expiring Total MW Expiring Percentage of Total MW Annualized GAAP TCV Rent Expiring Percentage of TCV Annualized Rent 2025 359 5.9 1.1% 17,070 2.0% 2026 808 29.3 5.5% 88,857 10.5% 2027 217 19.4 3.6% 63,052 7.4% 2028 220 53.1 9.9% 113,415 13.4% 2029 74 50.9 9.5% 53,940 6.4% 2030 51 60.6 11.3% 80,289 9.5% 2031 5 5.9 1.1% 10,159 1.2% Thereafter 29 312.1 58.0% 421,178 49.5% Total 1,763 537.2 100.0% $847,959 100.0% WALE: 10.0 years Data Center Leasing Activity Summary Q2 2025 YTD 2025 Transaction Count GAAP MRR kW $ / kW / Month Transaction Count GAAP MRR kW $ / kW / Month New/expansion leases signed 89 $576 2,325 $248 205 $1,297 6,025 $215 Commenced leases 100 3,376 23,215 145 195 5,207 34,881 149 Commenced Built to Suit leases — — — — — — — — Renewed leases 300 5,598 25,215 222 587 8,577 34,724 247 Churn 0.5% 0.8% Cash Mark to Market 13.1% 15.0% GAAP Mark to Market 19.5% 22.0% AZP-3 Rendering Section VII - Data Center Customer and Portfolio Metrics investors.ironmountain.com Q2 2025 Supplemental Financial Information 21

Data Center Operating Portfolio Stabilized Pre-Stabilized Total Leaseable MW Leased % by MW Leaseable MW Leased % by MW Leaseable MW Leased % by MW Boyers and Other WPA-1 and Other 14.2 74.9% — — 14.2 74.9% Phoenix AZP-1 41.0 100.0% — — 41.0 100.0% AZP-2 46.5 100.0% — — 46.5 100.0% Scottsdale AZS-1 5.7 100.0% — — 5.7 100.0% Denver DEN-1 11.3 88.9% — — 11.3 88.9% New Jersey NJE-1 16.8 85.8% 4.0 62.5% 20.8 81.3% Northern Virginia VA-1 12.4 100.0% — — 12.4 100.0% VA-2 36.0 100.0% — — 36.0 100.0% VA-3 44.0 100.0% — — 44.0 100.0% VA-4 (1) 32.0 100.0% — — 32.0 100.0% VA-5 (1) 40.0 100.0% — — 40.0 100.0% VA-6 Phase 1 (2) 32.0 96.9% — — 32.0 96.9% VA-7 18.0 100.0% — — 18.0 100.0% Amsterdam AMS-1 13.1 96.8% — — 13.1 96.8% London LON-1 8.7 96.3% — — 8.7 96.3% LON-2 18.0 100.0% — — 18.0 100.0% Frankfurt FRA-1 (3) 27.0 100.0% — — 27.0 100.0% FRA-2 9.8 100.0% — — 9.8 100.0% Singapore SIN-1 6.8 100.0% — — 6.8 100.0% Madrid MAD-1 1.0 45.0% — — 1.0 45.0% India Web Werks 1.5 100.0% 10.4 45.3% 11.9 52.2% Total Data Center Properties 435.8 97.9% 14.4 50.1% 450.2 96.3% (1) VA-4/5 are held by a consolidated joint venture. (2) VA-6 data center is held by a consolidated joint venture. (3) FRA-1 data center is an unconsolidated joint venture. Total Potential Capacity - Megawatts Q2 2025 Q2 2024 Operating Portfolio 450.2 265.7 Under Construction 201.5 305.5 Held for Development 628.2 346.6 Total Data Center Portfolio 1,279.9 917.8 Section VII - Data Center Customer and Portfolio Metrics investors.ironmountain.com Q2 2025 Supplemental Financial Information 22

Data Center Expansion and Development Activity Project / Facilities MW Under Construction MW Pre- leased % Pre- Leased Investment in Q2 2025 ($M) Cumulative Investment ($M) Total Expected Investment ($M) (3) Expected Completion Expected Stabilization MW Held for Development Data Center Expansion Amsterdam AMS-1 Phase 4 10.0 — — $12.9 $72.8 $156.6 Q2 2027 Q2 2028 — Madrid MAD-1 Phase 1 2.0 0.3 14.0% $3.2 $29.6 $31.9 Q3 2025 Q3 2026 — India Web Werks 2.5 — — — — — 2.9 All Other Facilities (1) 1.0 1.0 — — — — 20.4 Total Expansion 15.5 1.3 8.3% $16.1 $102.4 $188.5 23.3 New Development Phoenix AZP-3 Phase 1 18.0 18.0 100.0% $25.4 $202.8 $297.5 Q4 2025 Q4 2025 — AZP-3 Phase 2 10.0 10.0 100.0% $3.5 $33.3 $60.1 Q2 2026 Q2 2026 — AZP-3 Phase 3 8.0 8.0 100.0% $5.2 $25.8 $47.4 Q3 2026 Q3 2026 — Amsterdam AMS-2 — — — — — — 20.0 Chicago CHI-2 Phase 1 12.0 — — $28.6 $173.5 $195.4 Q4 2025 Q4 2026 — CHI-2 Future Phases — — — — — — 24.0 London LON-2 Phase 3 9.0 9.0 100.0% $2.8 $67.3 $70.1 Q4 2025 Q4 2025 — LON-3 Future Phases 25.0 25.0 100.0% $10.5 $91.0 $391.9 Q4 2026 Q4 2026 — Madrid MAD-1 10.0 — — $17.7 $45.7 $145.4 Q4 2026 Q4 2027 — MAD-1 Future Phases — — — — — — 66.0 Northern Virginia VA-7 Phase 2 (2) 18.0 18.0 100.0% $17.6 $89.7 $115.1 Q4 2025 Q4 2025 — VA-9 28.0 — — $13.7 $19.0 $346.9 Q1 2027 Q1 2028 — VA Future Phases (1) 32.0 32.0 100.0% — — — 146.0 India Web Werks — — — — — — 148.9 Miami MIA-1 16.0 — — $17.5 $39.0 $193.0 Q3 2026 Q3 2027 — Richmond RIC Future Phases — — — — — — 200.0 Total New Development 186.0 120.0 64.5% $142.3 $787.1 $1,862.8 604.9 Total Development 201.5 121.3 60.2% $158.4 $889.4 $2,051.3 628.2 (1) Includes megawatts pre-leased where construction is planned, but has not commenced. (2) VA-7 is held by a consolidated joint venture; construction costs are funded by the joint venture with Iron Mountain managing the construction. (3) Excludes cost associated with megawatts pre-leased where facility construction is planned, but has not commenced. Section VII - Data Center Customer and Portfolio Metrics investors.ironmountain.com Q2 2025 Supplemental Financial Information 23

Capitalization Revolving Credit Facility and Term Loan A Total Market Capitalization as of 06/30/2025 Capacity $3,250,000 # of Shares Outstanding 295,272 Outstanding $1,586,500 Share Price as of 06/30/25 $102.57 Letters of Credit $17,928 Total Market Capitalization $30,286,043 Remaining Capacity $1,645,572 Net Debt (1) $15,483,805 Interest Rate Spread (Prime) 0.75 % Total Enterprise Value $45,769,848 Interest Rate Spread (SOFR) 1.75 % Net Debt to Total Enterprise Value 33.8 % Weighted Average Interest Rate 6.08 % Adjusted EBITDA to Interest Expense 3.1x Maturity Date 3/18/2030 Total Enterprise Value to Adjusted EBITDA (2) 19.2x Credit Facility Fixed Charge Coverage Ratio 2.4x Net Total Lease-Adjusted Leverage Ratio 5.0x Fixed vs. Floating Rate Debt 77% 23% Fixed Rate Debt Floating Rate Debt Credit Rating S&P Moody's Corporate BB- Ba3 Senior Credit Facility BB Ba3 Outlook Stable Stable Latest Update 7/16/2025 10/10/2024 Total Long Term Debt Weighted Average Rates Weighted Average Interest 5.7 % Weighted Average Maturity 4.5 Years USD denominated 89 % Debt Maturity Profile ($ in Millions) (3) (4) (5) 775 371 1,871 1,576 2,077 3,025 2,839 1,350 1,200 24 21 Revolving Credit Facility and Term Loan A Bi-Lateral Loans Construction Loans IMDC AUD Term Loan B A/R Securitization USD Term Loan B (2031) Mortgage Notes Payable Senior Unsecured Notes 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2036 (1) Net debt is calculated as current portion of long-term debt of $777.9M plus long-term debt net of current portion of $14,818.2M plus deferred financing costs of $105.7M less cash and cash equivalents of $218.0M. (2) Total Enterprise Value to Adjusted EBITDA is calculated on a trailing twelve-month basis. (3) Excludes Deferred Financing Costs, Discounts, Financing Leases, Notes Payable and Other. (4) In addition to the above, the Company has approximately $113.3M of undrawn committed asset level financing for the construction of four Data Center assets in Northern Virginia. (5) All information as of June 30, 2025, except for the maturity date of the UK Bi-Lateral Facility, which was extended to 2028 on July 11, 2025. Section VIII - Capitalization and Debt Maturity Profile investors.ironmountain.com Q2 2025 Supplemental Financial Information 24

Quarterly Capital Expenditures Q2 2025 Q1 2025 Q/Q % Change Q2 2024 Y/Y % Change Growth: Data Center $376,983 $575,999 (34.6) % $294,758 27.9 % Real Estate 37,046 30,934 19.8 % 46,202 (19.8) % Innovation and Other 28,021 21,584 29.8 % 20,971 33.6 % Total Growth Capital Expenditures $442,050 $628,516 (29.7) % $361,931 22.1 % Recurring: Data Center $5,176 $3,067 68.8 % $3,598 43.9 % Real Estate 12,085 8,196 47.4 % 14,546 (16.9) % Non-Real Estate 17,533 16,820 4.2 % 18,832 (6.9) % Total Recurring Capital Expenditures $34,794 $28,083 23.9 % $36,976 (5.9) % Total Growth and Recurring Capital Expenditures $476,844 $656,600 (27.4) % $398,906 19.5 % Net Change in Prepaid and Accrued Capital Expenditures 79,912 18,167 n/a (2,150) n/a Total Cash Paid for Growth and Recurring Capital Expenditures $556,756 $674,767 (17.5) % $396,756 40.3 % Year to Date Capital Expenditures YTD 2025 YTD 2024 % Change Growth: Data Center $952,982 $571,388 66.8 % Real Estate 67,980 92,957 (26.9) % Innovation and Other 49,605 34,701 42.9 % Total Growth Capital Expenditures $1,070,567 $699,046 53.1 % Recurring: Data Center $8,243 $5,366 53.6 % Real Estate 20,281 23,908 (15.2) % Non-Real Estate 34,353 36,439 (5.7) % Total Recurring Capital Expenditures $62,877 $65,713 (4.3) % Total Growth and Recurring Capital Expenditures $1,133,444 $764,759 48.2 % Net Change in Prepaid and Accrued Capital Expenditures 98,079 13,142 n/a Total Cash Paid for Growth and Recurring Capital Expenditures $1,231,523 $777,901 58.3 % Section IX - Capital Expenditures investors.ironmountain.com Q2 2025 Supplemental Financial Information 25

Non-GAAP Measures and Definitions Non-GAAP measures are supplemental metrics designed to enhance our disclosures and to provide additional information that we believe to be important for investors to consider when evaluating our financial performance. These non-GAAP measures should be considered in addition to, but not as a substitute for, other measures of financial performance reported in accordance with accounting principles generally accepted in the United States of America (“GAAP”), such as operating income, income (loss) from continuing operations, net income (loss) or cash flows from operating activities from continuing operations (as determined in accordance with GAAP). SRP FLS Statement: We have made statements in this Supplemental Financial Information that constitute "forward-looking statements" as that term is defined in the Private Securities Litigation Reform Act of 1995 and other securities laws. These forward-looking statements concern our current expectations regarding our future results from operations, economic performance, financial condition, goals, strategies, investment objectives, plans and achievements. These forward-looking statements are subject to various known and unknown risks, uncertainties and other factors, and you should not rely upon them except as statements of our present intentions and of our present expectations, which may or may not occur. When we use words such as “believes”, “expects”, “anticipates”, “estimates”, “plans”, “intends”, "projects", “pursue”, “will” or similar expressions, we are making forward- looking statements. Although we believe that our forward-looking statements are based on reasonable assumptions, our expected results may not be achieved, and actual results may differ materially from our expectations. In addition, important factors that could cause actual results to differ from expectations include, among others: (i) our ability or inability to execute our strategic growth plan, including our ability to invest according to plan, grow our businesses (including through joint ventures or other co-investment vehicles), incorporate alternative technologies (including artificial intelligence) into our offerings, achieve satisfactory returns on new product offerings, continue our revenue management, expand and manage our global operations, complete acquisitions on satisfactory terms, integrate acquired companies efficiently and transition to more sustainable sources of energy; (ii) changes in customer preferences and demand for our storage and information management services, including as a result of the shift from paper and tape storage to alternative technologies that require less physical space or services activity; (iii) the costs of complying with and our ability to comply with laws, regulations and customer requirements, including those relating to data privacy and cybersecurity issues, as well as fire and safety and environmental standards; (iv) the impact of attacks on our internal information technology (“IT”) systems, including the impact of such incidents on our reputation and ability to compete and any litigation or disputes that may arise in connection with such incidents; (v) our ability to fund capital expenditures; (vi) the impact of our distribution requirements on our ability to execute our business plan; (vii) our ability to remain qualified for taxation as a real estate investment trust for United States federal income tax purposes (“REIT”); (viii) changes in the political and economic environments in the countries in which we operate and changes in the global political climate; (ix) our ability to raise debt or equity capital and changes in the cost of our debt; (x) our ability to comply with our existing debt obligations and restrictions in our debt instruments; (xi) the impact of service interruptions or equipment damage and the cost of power on our data center operations; (xii) the cost or potential liabilities associated with real estate necessary for our business; (xiii) unexpected events, including those resulting from climate change or geopolitical events, could disrupt our operations and adversely affect our reputation and results of operations; (xiv) failures to implement and manage new IT systems; (xv) other trends in competitive or economic conditions affecting our financial condition or results of operations not presently contemplated; and (xvi) the other risks described in our periodic reports filed with the SEC, including under the caption “Risk Factors” in Part I, Item 1A of our Annual Report. Except as required by law, we undertake no obligation to update any forward- looking statements appearing in this Supplemental Financial Information. Acquisition and Integration Costs: We define Acquisition and Integration Costs as 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. Adjusted Earnings Per Share, or Adjusted EPS: We define Adjusted EPS as reported earnings per share fully diluted from net income (loss) attributable to Iron Mountain Incorporated (inclusive of our share of adjusted losses (gains) from our unconsolidated joint ventures) and excluding certain items, specifically: (i) Acquisition and Integration Costs; (ii) Restructuring and other transformation; (iii) Loss (gain) on disposal/write-down of property, plant and equipment, net (including real estate); (iv) Other expense (income), net; (v) Stock-based compensation expense; (vi) Non-cash amortization related to derivative instruments; (vii) Tax impact of reconciling items and discrete tax items; and (viii) Amortization related to the write-off of certain customer relationship intangible assets. We do not believe these excluded items to be indicative of our ongoing operating results, and they are not considered when we are forecasting our future results. We believe Adjusted EPS is of value to our current and potential investors when comparing our results from past, present and future periods. Non-Cash Amortization of Derivative Instruments: Includes amortization on instruments such as cross-currency swap agreements designated as a hedge of net investment. Adjusted EBITDA and Adjusted EBITDA Margin: We define Adjusted EBITDA as net income (loss) before interest expense, net, provision (benefit) for income taxes, depreciation and amortization (inclusive of our share of Adjusted EBITDA from our unconsolidated joint ventures), and excluding certain items we do not believe to be indicative of our core operating results, specifically: (i) Acquisition and Integration Costs; (ii) Restructuring and other transformation; (iii) Loss (gain) on disposal/write-down of property, plant and equipment, net (including real estate); (iv) Other expense (income), net; (v) Stock-based compensation expense; and (vi) Intangible impairments. Adjusted EBITDA Margin is calculated by dividing Adjusted EBITDA by total revenues. We use multiples of current or projected Adjusted EBITDA in conjunction with our discounted cash flow models to determine our estimated overall enterprise valuation and to evaluate acquisition targets. We believe Adjusted EBITDA and Adjusted EBITDA Margin provide our current and potential investors with relevant and useful information regarding our ability to generate cash flows to support business investment. These measures are an integral part of the internal reporting system we use to assess and evaluate the operating performance of our business. Funds From Operations, FFO (Nareit), and FFO (Normalized): Funds from operations ("FFO") is defined by the National Association of Real Estate Investment Trusts as net income (loss) excluding depreciation on real estate assets, losses and gains on sale of real estate, net of tax, and amortization of data center leased-based intangibles (“FFO (Nareit)”). We calculate our FFO measures, including FFO (Nareit), adjusting for our share of reconciling items from our unconsolidated joint ventures. FFO (Nareit) does not give effect to real estate depreciation because these amounts are computed, under GAAP, to allocate the Section X - Appendix and Definitions investors.ironmountain.com Q2 2025 Supplemental Financial Information 26

cost of a property over its useful life. Because values for well-maintained real estate assets have historically increased or decreased based upon prevailing market conditions, we believe that FFO (Nareit) provides investors with a clearer view of our operating performance. Our most directly comparable GAAP measure to FFO (Nareit) is net income (loss). We modify FFO (Nareit), as is common among REITs seeking to provide financial measures that most meaningfully reflect their particular business ("FFO (Normalized)"). Our definition of FFO (Normalized) excludes certain items included in FFO (Nareit) that we believe are not indicative of our core operating results, specifically: (i) Acquisition and Integration Costs; (ii) Restructuring and other transformation; (iii) Loss (gain) on disposal/write-down of property, plant and equipment, net (excluding real estate); (iv) Other expense (income), net; (v) Stock-based compensation expense; (vi) Non-cash amortization related to derivative instruments; (vii) Real estate financing lease depreciation; (viii) Tax impact of reconciling items and discrete tax items; (ix) Intangible impairments; and (x) (Income) loss from discontinued operations, net of tax. FFO (Normalized) per share: FFO (Normalized) divided by weighted-average fully-diluted shares outstanding. Adjusted Funds From Operations, or AFFO: We define adjusted funds from operations or AFFO as FFO (Normalized) (1) excluding (i) non-cash rent expense (income); (ii) depreciation on non-real estate assets; (iii) amortization expense associated with customer and supplier relationship value, intake costs, acquisition of customer and supplier relationships, capitalized commissions and other intangibles; (iv) amortization of deferred financing costs and debt discount/ premium; (v) revenue reduction associated with amortization of customer inducements and above- and below-market data center leases; and (vi) the impact of reconciling to normalized cash taxes; and (2) including recurring capital expenditures. We also adjust for these items to the extent attributable to our portion of unconsolidated ventures. We believe that AFFO, as a widely recognized measure of operations of REITs, is helpful to investors as a meaningful supplemental comparative performance measure to other REITs, including on a per share basis. AFFO should be considered in addition to, but not as a substitute for, other measures of financial performance reported in accordance with GAAP, such as operating income, net income (loss) or cash flows from operating activities (as determined in accordance with GAAP). AFFO per share: Calculated as AFFO divided by weighted-average fully-diluted shares outstanding. Terminations/Permanent Withdrawal Fees: Revenue from the preparation, documentation, and permanent withdrawal of records. Business Segments: The Global Records and Information Management ("Global RIM"): Records Management, 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. Data Management, 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"). Global Digital Solutions, 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 ("Global Digital Solutions"). Secure Shredding, 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. Media and Archive Services, 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 ("Media and Archive Services"). Consumer Storage, provides on-demand, valet storage for consumers ("Consumer Storage") utilizing data analytics and machine learning to provide effective customer acquisition and a convenient and seamless consumer storage experience. Global Data Center Business: 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. Corporate and Other: Consists primarily of our Fine Arts and asset lifecycle management ("ALM") businesses and other corporate items ("Corporate and Other"). Our Fine Arts business provides technical expertise in the handling, installation and storing of art. Our ALM business 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 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. Corporate and Other includes costs related to executive and staff functions, including finance, human resources and IT, which benefit the enterprise as a whole. Section X - Appendix and Definitions investors.ironmountain.com Q2 2025 Supplemental Financial Information 27

Capital Expenditures and Investments: Our business requires capital expenditures to support our expected storage rental revenue and service revenue growth and ongoing operations, new products and services and increased profitability. The majority of our capital goes to support business line growth and our ongoing operations. Additionally, we invest capital to acquire or construct real estate. We also expend capital to support the development and improvement of products and services and projects designed to increase our profitability. These expenditures are generally discretionary in nature. We categorize our capital expenditures as follows: Growth Investment: Data Center - Expenditures primarily related to investments in the construction of data center facilities (including the acquisition of land), as well as investments to drive revenue growth, expand capacity or achieve operational or cost efficiencies. Real Estate - Expenditures primarily related to investments in land, buildings, building and leasehold improvements and racking structures to grow our revenues, extend the useful life of an asset or achieve operational or cost efficiencies. Innovation and Other - Discretionary capital expenditures for new products and services as well as computer hardware and software to drive revenue growth, expand capacity or to achieve operational cost efficiencies in businesses other than our data center business. Integration costs of acquisitions are also included. Recurring: Data Center - Expenditures related to the replacement of equivalent components and overall maintenance of existing data center assets. Real Estate - Expenditures primarily related to the replacement of components of real estate assets such as buildings, building and leasehold improvements and racking structures. Non-Real Estate - Expenditures primarily related to the replacement of containers and shred bins, warehouse equipment, fixtures, computer hardware, or third-party or internally-developed software assets that support the maintenance of existing revenues or avoidance of an increase in costs. Constant Currency: Adjusts results to normalize Fx impacts across comparable periods. Data Center Business Definitions: Leaseable MW - Represents the amount of critical power capacity available for customer use, measured in megawatts (MW). Monthly Recurring Revenue (MRR) - Defined as recurring contractual revenue under existing commenced customer leases, including rent, power, and other recurring data center services. Pre-leased - A lease on data center capacity that is signed before construction has completed. Pre-Stabilized - A building recently placed in service which has not yet reached 85% leased or 24 months in service. Rental Churn Rate - Represents data center leases which are not renewed or are terminated during the period. Rental churn is calculated based on the MRR terminated in the period, compared with total MRR at the beginning of the period. TCV - “Total Contract Value” represents total revenue contracted for active contracts through the contract term, not including renewals or extensions, but including fixed power charges. Total potential MW - Total amount of existing and planned critical power capacity at full build-out, measured in megawatts. WALE - “Weighted Average Lease Expiry” (in years) is calculated on a revenue basis, using annual GAAP revenue of all in-place contracts, excluding utility reimbursements. EBITDAR: Calculated using a trailing four fiscal quarter basis earnings before interest, taxes, depreciation and amortization and rent expense (“EBITDAR”) of our consolidated subsidiaries, other than those we have designated as “Unrestricted Subsidiaries” as defined in our Credit Agreement, subject to certain adjustments and exclusions, which make the calculation of financial performance for purposes of EBITDAR calculations not directly comparable to our presentation of Adjusted EBITDA. Credit Facility Fixed Charge Coverage Ratio: Calculated using a trailing four fiscal quarter basis EBITDAR divided by scheduled amortization, interest expense related to outstanding debt and preferred equity, if any, and rent expenses of our consolidated subsidiaries, other than those we have designated as “Unrestricted Subsidiaries” as defined in our Credit Agreement. Net Lease-Adjusted Leverage Ratio: Calculated as net debt, including the capitalized value of lease obligations, of our consolidated subsidiaries, other than those we have designated as “Unrestricted Subsidiaries” as defined in our Credit Agreement, plus six times rent expenses divided by EBITDAR. Organic Revenue Growth: Our organic revenue growth rate, represents the year-over-year growth rate of our revenues excluding the impact of business acquisitions, divestitures and foreign currency exchange rate fluctuations. Our organic revenue growth rate includes the impact of acquisitions of customer relationships. Records Management Retention Rate: Calculated as one minus the result of dividing the total number of cubic feet of records removed from inventory due to customer terminations and destructions in a one-year period by the total number of cubic feet of records in storage at the beginning of the period. Storage Rev/NOI per Sq. Ft.: Calculated as either storage revenue or Storage NOI (as defined below) divided by the quarterly building square foot average for storage products. Section X - Appendix and Definitions investors.ironmountain.com Q2 2025 Supplemental Financial Information 28

Service Profit and Margin: The Gross Profit and Margin attributable to the global service business. Calculated as follows: Total Revenues from Adjusted Service Activities - Service Cost of Sales = Service Gross Profit ($) / Total Revenues from Adjusted Service Activities = Service Gross Margin (%) Storage Net Operating Income, or Storage NOI: Storage NOI is defined as revenue from rental activities (storage rental revenue, termination fees and permanent withdrawal fees) less storage rental costs. Storage rental costs include facility costs (excluding rent), storage rental labor, other storage costs and allocated overhead. Storage NOI is commonly used in the REIT industry and enables investors to understand and value the income generated from the company’s real estate. Storage Profit and Margin: Gross Profit and Margin attributable to the global storage business. Calculated as follows: Total Revenue from Adjusted Storage Rental Activities - Storage Rental Cost of Sales = Storage Rental Gross Profit ($) / Total Revenue from Adjusted Storage Rental Activities = Storage Rental Gross Margin (%) Tax Rates: Effective Tax Rate - GAAP tax rate for the period calculated as tax expense or benefit for the quarter (total of current and deferred tax provisions), including discrete items, and divided by profit before tax for the period. Structural Tax Rate - Estimated tax rate for the full fiscal year calculated based on forecasted ordinary income and forecasted tax expense/benefit excluding any significant unusual or infrequently occurring items (i.e., discrete items) and items recognized net of tax on the financials (i.e., discontinued operations). Total Storage Volume: Iron Mountain’s comprehensive portfolio of physical storage, including Global RIM and Corporate and Other, calculated on an absolute basis in cubic feet. Section X - Appendix and Definitions investors.ironmountain.com Q2 2025 Supplemental Financial Information 29