American Tower (AMT): what its 10-K says it depends on

Customers

AT&T Inc.

earns from · 17%named as a risk

The following is a list of significant customers (representing at least 10% of revenue in any of the last three years) and the percentage of our total revenues for the specified time periods received from these customers:Risk factors (Item 1A)

Also named by CNP, DY, GLIBK, TMUS, VZ

Verizon Communications Inc.

earns from · 14%named as a risk

The following is a list of significant customers (representing at least 10% of revenue in any of the last three years) and the percentage of our total revenues for the specified time periods received from these customers:Risk factors (Item 1A)

Also named by DY, GLIBK, TMUS

T-Mobile US, Inc.

earns from · 18%named as a risk

The following is a list of significant customers (representing at least 10% of revenue in any of the last three years) and the percentage of our total revenues for the specified time periods received from these customers:Risk factors (Item 1A)

Also named by VZ

América Móvil

earns from · 71% of Latin America property segment revenuenamed as a risk

•Latin America: América Móvil; AT&T; Telefónica; and TIM S.p.A. accounted for an aggregate of 71% of Latin America property segment revenue.Business (Item 1)

Also named by T

Telefónica S.A.

earns from · 10%named as a risk

•Europe: Telefónica S.A. (“Telefónica”) accounted for an aggregate of 70% of Europe property segment revenue.Business (Item 1)

AT&T Mexico

earns from · approximately $300 million of tenant revenue in 2025named as a risk

AT&T Mexico, which represented approximately $300 million of tenant revenue in 2025, is challenging the calculation of the monthly lease amount established under our Master Lease Agreement with AT&T Mexico (the “MLA”), as well as certain other provisions of the MLA, seeking rent abatement both retroactively and prospectively, and withheld certain tower rents during 2025.Risk factors (Item 1A)

DISH Network Corporation

earns from · approximately 2% and 4% of our total annual property revenue and total annual U.S. & Canada property revenuenamed as a risk

DISH represented approximately 2% and 4% of our total annual property revenue and total annual U.S. & Canada property revenue, respectively, for 2025.Risk factors (Item 1A)

Bharti Airtel Limited

earns from · 81% of Africa & APAC property segment revenuenamed as a risk

•Africa & APAC: Bharti Airtel Limited (“Airtel”); and MTN Group Limited (“MTN”) accounted for an aggregate of 81% of Africa & APAC property segment revenue.Business (Item 1)

MTN Group Limited

earns from · 81% of Africa & APAC property segment revenuenamed as a risk

•Africa & APAC: Bharti Airtel Limited (“Airtel”); and MTN Group Limited (“MTN”) accounted for an aggregate of 81% of Africa & APAC property segment revenue.Business (Item 1)

TIM S.p.A.

earns from · 71% of Latin America property segment revenuenamed as a risk

•Latin America: América Móvil; AT&T; Telefónica; and TIM S.p.A. accounted for an aggregate of 71% of Latin America property segment revenue.Business (Item 1)

Other companies

CoreSite Realty Corporation

operates in · 10% of our total revenuesnamed as a risk

Our data centers segment represented 10% of our total revenues for the year ended December 31, 2025.Risk factors (Item 1A)

Competitors

SBA Communications Corporation

competes withnamed as a risk

We compete, both for new business and for the acquisition of assets, with other public tower companies, such as Crown Castle International Corp., SBA Communications Corporation, Vertical Bridge, Telesites S.A.B. de C.V. and Cellnex Telecom, S.A., wireless carrier tower consortia and private tower companies, private equity sponsored firms, carrier-affiliated tower companies, independent wireless carriers, tower owners, broadcasters and owners of non-communications sites, including rooftops, utility towers, water towers and other alternative structures.Business (Item 1)

Also named by CCI

Crown Castle International Corp.

competes withnamed as a risk

We compete, both for new business and for the acquisition of assets, with other public tower companies, such as Crown Castle International Corp., SBA Communications Corporation, Vertical Bridge, Telesites S.A.B. de C.V. and Cellnex Telecom, S.A., wireless carrier tower consortia and private tower companies, private equity sponsored firms, carrier-affiliated tower companies, independent wireless carriers, tower owners, broadcasters and owners of non-communications sites, including rooftops, utility towers, water towers and other alternative structures.Business (Item 1)

Cellnex Telecom, S.A.

competes withnamed as a risk

We compete, both for new business and for the acquisition of assets, with other public tower companies, such as Crown Castle International Corp., SBA Communications Corporation, Vertical Bridge, Telesites S.A.B. de C.V. and Cellnex Telecom, S.A., wireless carrier tower consortia and private tower companies, private equity sponsored firms, carrier-affiliated tower companies, independent wireless carriers, tower owners, broadcasters and owners of non-communications sites, including rooftops, utility towers, water towers and other alternative structures.Business (Item 1)

Places

Latin America

operates in · 15%named as a risk

Inflation impacts could also create foreign exchange rate instability in our international markets, including in markets such as Africa and Latin America, that could, in turn, depress the value of that market’s currency, thereby adversely impacting our business, results of operations, financial condition or the underlying value of foreign subsidiaries.Risk factors (Item 1A)

Also named by DCI, DOW, EZPW, FLS, MCO, SNEX, SOFI, UBER and 2 more

Africa

operates in · 27,857 communications sites in Africa & APACnamed as a risk

Inflation impacts could also create foreign exchange rate instability in our international markets, including in markets such as Africa and Latin America, that could, in turn, depress the value of that market’s currency, thereby adversely impacting our business, results of operations, financial condition or the underlying value of foreign subsidiaries.Risk factors (Item 1A)

Also named by SEB

United States and Canada

concentrated in · 49%

Our property segments accounted for the following percentage of consolidated total revenue for the years ended December 31,: 2025 2024 2023Business (Item 1)

Also named by AFL, BBW, COST, DCI, DE, FISV, NFLX, OWL

Hazards

Hurricanes, floods, earthquakes and wildfires

named as a risk

Our towers, data centers, other telecommunications assets and computer systems are subject to risks associated with natural disasters, such as hurricanes, ice and windstorms, tornadoes, floods, earthquakes and wildfires, as well as other unforeseen events, such as the potential adverse effects of pandemics and acts of terrorism.Risk factors (Item 1A)

Commodities and inputs

Euro

exposed to its price · 7.5 billion EUR (approximately $8.8 billion) denominated debt outstandingnamed as a risk

As of December 31, 2025, we have 7.5 billion EUR (approximately $8.8 billion) denominated debt outstanding, of which approximately 4.7 billion EUR (approximately $5.5 billion) is designated as a non-derivative net investment hedge.Market risk (Item 7A)

Also named by ABBV, ABNB, ABT, ADBE, ADI, AME, AMG, AMGN and 186 more

Foreign currency exchange rates

exposed to its price · 31% of our revenues and 40% of our total operating expensesnamed as a risk

For the year ended December 31, 2025, 31% of our revenues and 40% of our total operating expenses were denominated in foreign currencies.Market risk (Item 7A)

Also named by ADP, CPAY, DPZ, DVA, GLW, HLIO, LNN, PFG and 1 more

Electric power for data centers

depends onnamed as a risk

Difficulties in securing contracted energy or obtaining adequate capacity for future data center developments may adversely affect our operations, financial performance and customer relationships.Risk factors (Item 1A)

Also named by PLD

Power and fuel

exposed to its price

Our costs typically include ground rent (which is primarily fixed under long-term lease agreements with annual cost escalations) and power and fuel costs, some or all of which may be passed through to our tenants, as well as property taxes and repair and maintenance expenses.Business (Item 1)

Regulators

Federal Aviation Administration (FAA)

subject tonamed as a risk

Towers requiring pre-approval must be registered with the FCC and maintained in accordance with FAA standards.Business (Item 1)

Also named by ACHR, AIR, ALK, AVAV, BA, BRK/B, CCI, CW and 27 more

Federal Communications Commission (FCC)

subject tonamed as a risk

In the United States, the construction of new towers or modifications to existing towers may require pre-approval by the Federal Communications Commission (“FCC”) and the Federal Aviation Administration (“FAA”), depending on factors such as tower height and proximity to public airfields.Business (Item 1)

Also named by AIOT, ANET, ASTS, CCI, CMCSA, DIS, ECHO, EXTR and 26 more

Laws and programs

REIT qualification (Internal Revenue Code)

subject to · at least 90% of our REIT taxable incomenamed as a risk

If, in any taxable year, we fail to qualify for taxation as a REIT and are not entitled to relief under the Code:Risk factors (Item 1A)

Also named by ABR, CCI, DLR, ENSG, FPI, KIM, LAMR, O and 6 more

2021 Multicurrency Credit Facility

$380.0 millionnamed as a risk

Variable rate debt as of December 31, 2025 primarily consisted of $380.0 million under the 2021 Multicurrency Credit Facility, $1.0 billion under the 2021 Term Loan, $4.0 million under the CoreSite DE1 Note and $1.2 million under the Bangladesh Term Loan.Market risk (Item 7A)

Americans with Disabilities Act (ADA)

subject tonamed as a risk

Our U.S. data center facilities and related assets are subject to various federal, state and local regulations, such as state and local fire and life safety regulations and Americans with Disabilities Act (“ADA”) federal requirements.Business (Item 1)

Also named by CMG, DRI, ELS, HHH, HLT, LLYVA, LYV, PLD and 3 more

OECD Pillar 2 Rules

subject tonamed as a risk

Beginning in fiscal year 2026, the U.S. income of non-excluded entities may result in material Top-Up Taxes; however, on January 5, 2026, the OECD announced a comprehensive Side-by-Side Safe Harbor that, if enacted, would exempt U.S.-parented multinational companies from certain Top-Up Taxes under the Pillar 2 Rules beginning January 1, 2026.Risk factors (Item 1A)

South Africa Broad-Based Black Economic Empowerment Act

subject tonamed as a risk

For example, in South Africa, the Broad-Based Black Economic Empowerment Act, 2003 (the “BBBEE Act”) has established a legislative framework for the promotion of economic empowerment of South African citizens disadvantaged by Apartheid.Business (Item 1)

Telecommunications Act of 1996

subject to

In the United States, the Telecommunications Act of 1996 prohibits any action by state and local authorities that would discriminate between different providers of wireless services or ban altogether the construction, modification or placement of communications sites.Business (Item 1)

Also named by CCI

Technology

RAN sharing

named as a risk

In addition, extensive sharing of site infrastructure through RAN sharing, roaming or resale arrangements among wireless service providers, including due to increases in advanced network technology such as 5G, as an alternative to leasing our communications sites, without compensation to us, may cause new lease activity to slow if carriers utilize shared equipment rather than deploy new equipment, or may result in the decommissioning of equipment on certain existing sites because portions of the customers’ networks may become redundant.Risk factors (Item 1A)

5G

earns from

In the United States, incremental carrier network activity is being driven by ongoing 5G network deployments.Business (Item 1)

Also named by CCI, QCOM