AMT · CIK 1053507
What American Tower Corporation told the SEC could break it.
American Tower's exposure concentrates in its tenants: a handful of wireless carriers — T-Mobile at 18%, AT&T at 17%, Verizon at 14% and Telefónica at 10% — together made up roughly 59% of 2025 revenue, so carrier financial trouble, consolidation or non-renewal would weigh directly on results. That same dependence is the source of its largest disclosed dispute, an arbitration with AT&T Mexico — about $300 million of 2025 tenant revenue — over how monthly lease amounts are calculated. The rest of its register is operational and regulatory: reliance on third-party power, utilities and landlords for its data centers, and FCC/FAA approval and environmental regimes governing tower construction.
4 self-disclosed vulnerabilities, pulled from its own filings, each in the company’s words, with the source. This is the risk register almost nobody reads.
In its own words
What could break it.
Customer concentration
- top-4 carriers ~59% of revenue — T-Mobile 18%, AT&T 17%, Verizon 14%, Telefónica 10%medium
American Tower derives a large portion of revenue from a small number of customers — T-Mobile (18%), AT&T (17%), Verizon Wireless (14%) and Telefónica (10%) together ~59% in 2025 — so carrier financial difficulties, bankruptcy, consolidation or non-renewal could materially reduce revenue.
“The following is a list of significant customers (representing at least 10% of revenue in any of the last three years)... T-Mobile 18 % 19 % 19 % AT&T 17 % 18 % 18 % Verizon Wireless 14 % 13 % 14 % Telefónica 10 % 10 % 10 %”
SEC filing →As of 2026
Litigation
- AT&T Mexico arbitration — disputing monthly lease calculation; ~$300M of 2025 tenant revenuemedium
American Tower is in an arbitration with AT&T Mexico (AT&T Comunicaciones Digitales and related entities), which represented ~$300 million of tenant revenue in 2025 and is challenging the monthly lease-amount calculation under their Master agreement — an adverse outcome could reduce revenue.
“we are currently engaged in a legal dispute (the “Arbitration”) with one of our customers in Mexico, AT&T Comunicaciones Digitales, S. de R.L. de C.V. and related entities (collectively, “AT&T Mexico”). AT&T Mexico, which represented approximately $300 million of tenant revenue in 2025, is challenging the calculation of the monthly lease amount”
SEC filing →As of 2026
Supplier concentration
- data-center power/energy + third-party utility/internet dependence; landlord maintenance of leased data centersmedium
American Tower's data-center business relies on third parties, governmental entities and suppliers for sufficient power (and on third-party internet/telecom/utility providers); it also depends on landlords to maintain leased data centers — difficulties securing contracted energy/capacity or inadequate landlord maintenance could disrupt operations or force early exits.
“we rely on third parties, governmental entities and suppliers to provide sufficient power for our data centers and to support future expansion... Additionally, we rely on third-party providers for internet, telecommunications and utilities, and any failure by these providers could adversely affect our business”
SEC filing →As of 2026
Regulatory & policy
- FCC/FAA tower construction/registration regulation + environmental review; international equivalentslow
New-tower construction and modifications may require FCC and FAA pre-approval (registration, height/airfield-proximity, FAA-standard maintenance) plus environmental review in the U.S. and similar regimes abroad; non-compliance can bring monetary penalties or site-deconstruction orders, and AMT must also meet REIT 90%-distribution requirements.
“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”)... Non-compliance with applicable tower-related requirements may lead to monetary penalties or site deconstruction orders.”
SEC filing →As of 2026
The hidden graph
Who it depends on, and who depends on it.
Relationships surfaced from filings, including ones disclosed by the other side, which is how the non-obvious ones come to light.
Its customers
“For the year ended December 31, 2025, our top four customers by total revenue were T-Mobile (18%), AT&T (17%), Verizon Wireless (14%) and Telefónica (10%).”
Cited →“For the year ended December 31, 2025, our top four customers by total revenue were T-Mobile (18%), AT&T (17%), Verizon Wireless (14%) and Telefónica (10%).”
Cited →“For the year ended December 31, 2025, our top four customers by total revenue were T-Mobile (18%), AT&T (17%), Verizon Wireless (14%) and Telefónica (10%).”
Cited →
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