#1MANAGE IRON MOUNTAIN INFORMA Investor Presentation Q2 2021 IRON MOUNTAINⓇ#22 Forward looking statements We have made statements in this presentation 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 operations, economic performance, financial condition, goals, beliefs, future growth strategies, investment objectives, plans and current expectations, such as our (1) 2021 guidance as well as our expectations for growth, including growth opportunities and growth rates for revenue by segment, organic revenue, organic volume and other metrics, (2) expectations and assumptions regarding the impact from the COVID-19 pandemic on us and our customers, including on our businesses, financial position, results of operations and cash flows, (3) expected benefits, costs and actions related to, and timing of, Project Summit, (4) expectations as to our capital allocation strategy, including our future investments, leverage ratio, dividend payments and possible funding sources (including real estate monetization) and capital expenditures, (5) expectations regarding the closing of pending acquisitions, divestitures and investments, and (6) other forward-looking statements related to our business, results of operations and financial condition. 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" 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) the severity and duration of the COVID-19 pandemic and its effects on the global economy, including its effects on us, the markets we serve and our customers and the third parties with whom we do business within those markets; (ii) our ability to execute on Project Summit and the potential impacts of Project Summit on our ability to retain and recruit employees; (iii) our ability to remain qualified for taxation as a real estate investment trust for United States federal income tax purposes; (iv) 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; (v) our ability or inability to execute our strategic growth plan, including our ability to invest according to plan, incorporate new digital information technologies into our offerings, achieve satisfactory returns on new product offerings, continue our revenue management, expand internationally, complete acquisitions on satisfactory terms, integrate acquired companies efficiently and grow our business through joint ventures; (vi) changes in the amount of our capital expenditures; (vii) our ability to raise debt or equity capital and changes in the cost of our debt; (viii) the cost and our ability to comply with laws, regulations and customer demands, including those relating to data security and privacy issues, as well as fire and safety and environmental standards; (ix) the impact of litigation or disputes that may arise in connection with incidents in which we fail to protect our customers' information or our internal records or information technology systems and the impact of such incidents on our reputation and ability to compete; (x) changes in the price for our storage and information management services relative to the cost of providing such storage and information management services; (xi) changes in the political and economic environments in the countries in which our international subsidiaries operate and changes in the global political climate, particularly as we consolidate operations and move records and data across borders; (xii) our ability to comply with our existing debt obligations and restrictions in our debt instruments; (xiii) the impact of service interruptions or equipment damage and the cost of power on our data center operations; (xiv) the cost or potential liabilities associated with real estate necessary for our business; (xv) failures in our adoption of new IT systems; (xvi) other trends in competitive or economic conditions affecting our financial condition or results of operations not presently contemplated; and (xvii) 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 report. Reconciliation of Non-GAAP Measures: Throughout this release, Iron Mountain discusses (1) Adjusted EBITDA, (2) Adjusted Earnings per Share ("Adjusted EPS"), (3) Funds from Operations ("FFO Nareit"), (4) FFO (Normalized) and (5) Adjusted Funds from Operations ("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. IRON MOUNTAINⓇ#3Iron Mountain investor presentation Overview of the business ❖ Strategic shift accelerating growth Prudent capital allocation strategy Q1 2021 performance Note: Data as of 3/31/21 unless otherwise stated 3 IRON MOUNTAINⓇ#4Our Purpose To be our customers' most trusted partner for protecting and unlocking the value of what matters most to them in innovative and socially responsible ways#5Overview of the business IRON MOUNTAINⓇ#6Iron Mountain at a glance Global presence Significant size & scale Unmatched customer base ☐ ☐ ☐ ☐ ~730m Cu Ft global physical volume ~1,430 facilities 56 countries ~93m Sq Ft 6 continents (1) As of 5/10/2021 • ⚫ $12B (1) equity market capitalization ⚫ $21B (1) total enterprise • . • value $4.2B of revenue -280 owned facilities 15 operating Data Centers RMZ, FTSE NAREIT and S&P 500 Member ~225,000 customers Serving ~95% of Fortune 1,000 companies Customers from over 50 different industries IRON MOUNTAINⓇ 6#7Diversified business model Storage Business Mix Service Business Mix Total Revenue: $4.2B 12% 10% 3% Storage Revenue 66% of total Note: Numbers may not foot due to rounding. Records management Data management 24% Data center Adjacent businesses Global digital solutions Service Revenue 34% of total 43% Secure shred 18% 73% Consumer Storage 4% 9% IRON 7 MOUNTAINⓇ#8Durable records management business 8 ON MOUNTAI TAIN IRON MOUNTAIN TRON MCKINTOS 800 899 RON 800 8 NTAIN IRON MOUNTAIN RON MONTAN MOUNTAIN MOUN NTAIN IRON MOUNTAIN VICENDY MOUNDLY ROVAC IRON MOUNTA ANMENZE MOUNTAIN ON MY MONDAN . • ~710 million cubic feet of hard copy records archived 98 percent customer retention rate Steady Organic Revenue Growth supported by revenue management • Boxes remain in facilities for 15 years on average IRON MOUNTAINⓇ#9Durable global physical storage portfolio Cubic Feet (000s) 740,000 720,000 700,000 680,000 660,000 640,000 620,000 Worldwide Storage Volume 6 600,000 Q1 2020 Q2 2020 Q3 2020 Q4 2020 Q1 2021 Consumer and Other Adjacent Businesses Records and Information Management IRON MOUNTAINⓇ#10Iron Mountain Data Centers at a glance (1) 3 continents 5 countries 13 markets 10 internet exchanges 1,300+ customers 15 operational data centers Access to all major clouds 430+ employees 3.5 million gross square feet Interconnected DC network Industry leading sustainability programs 445 MW+ DC capacity (1) As of 3/31/21; does not reflect Web Werks JV that closed on 4/21/21 10 100% uptime SLA Industry leading compliance IRON MOUNTAINⓇ#11Key data center differentiators Interconnection, Cloud On-Ramps & Ecosystem Access to top global and local carriers, cloud and services providers 01 05 Sustainability 02 (Green Power Pass) 100% of the IMDC portfolio is powered by Renewable/Green Energy that is passed along to customers through Green Power Pass 03 O Global Footprint Data centers in the global markets that you need them. International hubs, top US markets, and smaller edge markets. 04 O Compliance Customer Support 11 Comprehensive compliance program certifies against the most rigorous frameworks in the industry, including globally certified ISO 27001 information security, ISO 14001 environmental, and 50001 energy management systems. We also report globally on service organizational controls, PCI-DSS compliance, and met FISMA HIGH and FedRAMP controls in the U.S. Certified experts offering Smart Hands operational services and white glove customer support IRON MOUNTAINⓇ#1212 Leasable MW -- 11.3 Significant data center expansion opportunity with current footprint Market Amsterdam Boyers and Other Chicago Denver 12.7 14.2 Held for Development Total Potential Capacity 34.0 Under Construction 6.1 15.2 11.2 25.4 36.0 36.0 -- 3.1 14.4 Frankfurt -- 9.0 18.0 27.0 London 9.1 9.0 18.0 36.1 New Jersey 16.1 0.2 9.3 25.6 Northern Virginia 16.4 6.0 123.0 145.4 Phoenix 49.7 19.0 26.0 94.7 Singapore 6.9 6.9 Total Data Center Portfolio (1) 136.4 49.3 259.8 445.5 Total portfolio capacity including expansion of ~445 MW IRON India Joint Venture with Web Werks closed Q2 2021 MOUNTAINⓇ (1) As of 3/31/21; does not reflect Web Werks JV that closed on 4/21/21#13Geographic data center expansion to India through JV 13 Web Works MUM-1 Web Works PUN 1 Note: Web Werks joint venture closed on 4/21/21 Works NCR-1 DATA IRON MOUNTAIN" CENTERS MUMBAI DELHI-NCR- PUNE SRINAGAR JAMMU AND KASHMIR DHARM-HMACHAL SMALA PRADESH CHANDIGARH PUNJAB HARYANA UTTARA- KHAND DEHRADUN Existing Markets Expansion Markets Web Werks INA ARUNACHAL PRADESH NEW DELHI JAIPUR LUCKNOW RAJASTHAN UTTAR PRADESH BIHAR PATNA DEPUR MPHAL JHARKHAND AGARTALA KZAML MADHYA PRADESH BHOPAL GANDHINAGAR KOLK BENGAL MAHARASHTRA TELANGANA ANDHRA PRADESH RNATAKA BANGALORE TAMIL NADU CHHATTISGARH ODISHA NAYA RAIPUR BHUBANESH HYDERABAD CHENNAI IRON MOUNTAINⓇ#14Project Summit overview Simplifying Global Structure • Combining Records and Information (RIM) operations under one global leader • Rebalancing resources to sharpen focus on higher growth areas Compelling Adjusted EBITDA Benefits $375M Expected annual run-rate benefits exiting 2021 • $165M delivered in 2020 $150M expected in 2021 $60M expected in 2022 $450M Total estimated charges to implement by end of 2021 $49M in 2019 $194M in 2020 $200M expected in 2021 14 Streamlining Management Structure for the Future • Consolidated the number of layers and reporting levels Creating a more dynamic agile organization that is better positioned to make faster decisions and execute its strategy in key growth areas Enhancing Customer Experience Providing customers with a more integrated experience • Leveraging technology to modernize processes for better alignment between new digital solutions and core business IRON MOUNTAINⓇ#15Strong sustainability focus • Green Power Pass solution in data center market to help customers manage their carbon footprint 15 • • • • • Part of RE100 Initiative - commitment to using renewable energy sources for 100% of our worldwide electricity 81% of our global electricity use – including 100% of the electricity used to power our Data Center business – was from renewable sources in 2020 - Recognized as a top 25 U.S. buyer of renewable energy and honored with the U.S. Department of Energy's Better Buildings Goal Achiever Award Reduced GHG emissions by 52% (since 2016) and achieved a 25% reduction in non-IT energy intensity, surpassing an original goal of 20% by 2026 Received a 100% on the Human Rights Campaign 2021 Corporate Equality Index for the fourth year in a row LOBAL THE GLO COMPACT EPA GREEN POWER017 Leadership Award Winner RE 100 WE SUPPORT Empowering Sustainable Decisions GRI CDP SCIENCE BASED TARGETS DRIVING AMBITIOUS CORPORATE CLIMATE ACTION IRON MOUNTAINⓇ#16Strategic shift accelerating revenue and EBITDA growth IRON MOUNTAINⓇ#17EMERGING FROM 2020 STRONGER THAN EVER ROAMENIIN#18Momentum to GO BEYOND 2020 THE YEAR OF RESILIENCE MOMENTUM 2021 THE YEAR OF GROWTH • Investments in innovation, culture, I&D - powered by Project Summit • Business growth in IMDC, Fine Art & Entertainment Services, Consumer, Global RIM 18 IRON MOUNTAINⓇ#19Our exciting growth opportunities 19 Data Centers Consumer Storage Secure IT Asset Disposition Fine Arts / Entertainment Services Global Commercial Excellence Digital Solutions IRON MOUNTAINⓇ#20Five-year growth momentum (2015-2020) Data Centers Expansion to 15 facilities in 3 continents since 2017 Total Addressable Market (TAM): $20B Consumer Joint venture with Makespace in 2019 Since 2019: 2.1M CF to 7.3M CF (3x growth) TAM: $35B+ . . Fine Art & IMES Art TAM: $1B Entertainment Services TAM: ~ $1B SITAD Media destruction, E-waste recycling, IT asset remarketing TAM: $10B 20 20 IRON MOUNTAINⓇ#21Our total addressable market (TAM) 21 21 2015 $10B ~ low-single % Global RIM TAM and revenue growth rate + 2020 $80B+ - 13% TAM and revenue growth rate of Data Centers, Fine Art & Entertainment Services, Consumer, SITAD, CSP, SMB IRON MOUNTAINⓇ#22Prudent capital allocation strategy IRON MOUNTAINⓇ#23Capital allocation strategy • Sustain the dividend at current level • Long-term target AFFO payout ratio of low to mid-60s • Long-term target leverage ratio of 4.5x-5.5x • Reinvest in the business through growth Capital Expenditures Invest in accretive M&A . Growth capital from capital recycling as well as debt finance in line with Adjusted EBITDA growth 23 23 IRON MOUNTAINⓇ#2424 24 Value creation through capital recycling Real Estate capital recycling strategy " IRM buys and sells with an ROI focus Recycles capital to create long-term value for shareholders Liquidity recycled into other real estate and data centers Capital recycling opportunities 2020 sales~$475 Million " " National U.S. portfolio of 13 properties 2.1 million square feet in total Sale leasebacks of highly desirable assets that we will continue to occupy through long-term leases Capitalized on favorable valuations of industrial assets in highly sought after markets Excess or inefficient real estate Better/best use - Sale generates outsized return Higher-use alternatives IRON MOUNTAINⓇ#25Balance sheet remains well positioned Balance Sheet Highlights as of 3/31/21 ~$1.8 billion of liquidity • ~85% Fixed Rate Debt . Net Lease Adjusted Leverage 6.0x 5.5x1 5.5x ~5.4x . 4.6% weighted average interest rate 7.6 years weighted-average maturity 5.3x J.P. Morgan REIT Composite IRM 2020 IRM Q1 2021 IRM 2021 Outlook 25 25 (1) Excluding the approximately $260 million of proceeds from a large sale leaseback transaction in the fourth quarter of 2020 that we plan to invest in 2021, net lease adjusted leverage was 5.5x. Source: J.P. Morgan REIT Weekly U.S. Real Estate report April 4, 2021 and company reports IRON MOUNTAINⓇ#26Q1 2021 performance IRON MOUNTAINⓇ#27Strong start to 2021 ($ in millions, except per share data) Three Months Ended 3/31/21 3/31/20 Y/Y % Change Storage Rental Revenue Service Revenue Total Revenue $708 $684 4% $374 $385 -3% $1,082 $1,069 1% Net Income $47 $65 -28% Adjusted EBITDA(1) $381 $366 4% Adjusted EBITDA Margin (1) 35.2% 34.2% +100 bps AFFO(1) $235 $231 2% AFFO per share(1) $0.81 $0.80 2% Dividend per share $0.62 $0.62 27 IRON MOUNTAINⓇ (1) Reconciliations for Adjusted EBITDA and AFFO to their respective GAAP measures can be found in the Supplemental Financial Information on pages 14 and 16, respectively.#28Increased 2021 guidance 2021 Guidance (1) ($ in millions, except per share data) Total Revenue Adjusted EBITDA AFFO AFFO Per Share 28 828 New $4,365 $4,515 $1,585 - $1,635 $955-$1,005 $3.28 - $3.45 5%-9% 7% -11% 8% -13% Y/Y % Change Previous $4,325 - $4,475 Y/Y % Change 4% -8% 7%-10% $1,575 - $1,625 7% -12% $945 - $995 $3.25-$3.42 7% -12% 6% -11% 2021 Guidance assumes: Organic storage rental revenue growth of 2% -4% Growth capital expenditures of $410 million, of which data center development is expected to be ~$300 million Recurring capital expenditures of $140 million Capital Recycling proceeds of $125 million Project Summit restructuring charges of ~ $200 million 2 Project Summit Adjusted EBITDA benefits of $150 million Note: Guidance as of May 6, 2021. (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. IRON MOUNTAINⓇ#2929 29 Key takeaways Proud of the continued performance of core business in spite of COVID Project Summit progressing well; on track to realize structural cost savings of $375 million per year exiting 2021 Our Global Strategic Accounts team continues to deliver growth in the core as well as new digital solutions Strong start to the year with 9 megawatts leased, and we continue to grow our data center footprint organically and through expansion into India Q1 results demonstrate accelerating earnings growth, the resiliency of our business, revenue growth in new areas, and the benefits of our culture IRON MOUNTAINⓇ#30IRON MOUNTAINⓇ [email protected] IRON MOUNTAINⓇ 30 30