Business Wire | Jan 21, 2021 06:00AM EST

Iron Mountain Incorporated Announces Tax Treatment of 2020 Distributions

Jan. 21, 2021

BOSTON--(BUSINESS WIRE)--Jan. 21, 2021--Iron Mountain Incorporated (NYSE: IRM), the global leader in storage and information management services, announced the tax treatment for all 2020 distributions on its common stock.

Form 1099 Form 1099 Form 1099 Form 1099 Form 1099 Form 1099 Box 1a Box 1b Box 2a Box 2b Box 3 Box 5

Ordinary Qualified Total Unrecaptured Section Total Taxable Taxable Capital Sec. 1250 Return of 199A Distribution Dividend Dividend^ Gain Gain^(2) Capital Dividend^ (1) Distribution (1)

Record Payment ($ per ($ per ($ per ($ per ($ per ($ per ($ perDate Date share) share) share) share) share) share) share)

Dec 16, Jan 2, $0.618500 $0.266089 $0.000094 $0.306311 $0.000073 $0.046100 $0.2659952019 2020

Mar 16, Apr 6, $0.618500 $0.266089 $0.000094 $0.306311 $0.000073 $0.046100 $0.2659952020 2020

Jun 15, Jul 2, $0.618500 $0.266089 $0.000094 $0.306311 $0.000073 $0.046100 $0.2659952020 2020

Sep 15, Oct 2, $0.618500 $0.266089 $0.000094 $0.306311 $0.000073 $0.046100 $0.2659952020 2020

Totals $2.474000 $1.064356 $0.000376 $1.225244 $0.000292 $0.184400 $1.063980

(1) Qualified Taxable Dividend and Section 199A Dividend are subsets of, and included in, Ordinary Taxable Dividend. (2) Unrecaptured Section 1250 Gain is a subset of, and included in, Total Capital Gain Distribution.

If you held common stock of Iron Mountain in your name at any time during 2020, an IRS Form 1099-DIV will be provided to you by Computershare, Iron Mountain's transfer agent. If you held shares in "street name" during 2020, the IRS form provided by your bank, brokerage firm or nominee may report only the gross distributions paid to you. Therefore, you may need the information included in this press release to properly complete your federal tax return.

Please note that federal tax laws affect taxpayers differently, and we cannot advise you on how distributions should be reported on your federal income tax return. Please also note that state and local taxation of REIT distributions vary and may not be the same as the federal treatment.

About Iron Mountain

Iron Mountain Incorporated (NYSE: IRM), founded in 1951, is the global leader for storage and information management services. Trusted by more than 225,000 organizations around the world, and with a real estate network of more than 90 million square feet across approximately 1,450 facilities in approximately 50 countries, Iron Mountain stores and protects billions of valued assets, including critical business information, highly sensitive data, and cultural and historical artifacts. Providing solutions that include secure records storage, information management, digital transformation, secure destruction, as well as data centers, cloud services and art storage and logistics, Iron Mountain helps customers lower cost and risk, comply with regulations, recover from disaster, and enable a more digital way of working. Visit www.ironmountain.com for more information.

View source version on businesswire.com: https://www.businesswire.com/news/home/20210121005129/en/

CONTACT: Investor Relations: Greer Aviv Senior Vice President, Investor Relations greer.aviv@ironmountain.com (617) 535-2887

CONTACT: Nathan McCurren Director, Investor Relations nathan.mccurren@ironmountain.com (617) 535-2997