Grizzly Bulls
Financial research concept

Tower Colocation and Amendment Billings

capture new leasing on existing tower assets, including new tenants and additional equipment from existing tenants.

By Lee BaileyPublished Sep 29, 2026
Research context

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Research date
Sep 29, 2026Use the dated article and cited sources for the definition, examples, and stated limitations.
Operating-model context
10 connected conceptsPart of the reviewed Wireless Tower Leasing Economics; issuer definitions remain distinct where disclosed.
Company examples
2 reviewed companiesRelationships reflect supported examples, not a normalized cross-company KPI ranking.
  1. Existing-site leasing is the core operating-leverage engine
  2. New leasing should not be confused with portfolio expansion
  3. Part of the Wireless Tower Leasing Economics
  4. See It in Company Research
  5. Continue Research

Tower colocation and amendment billings are incremental lease billings generated when a new tenant takes space on an existing communications site or an existing tenant adds equipment.

American Tower reported $63M of colocations and amendments in its second-quarter 2026 tenant-billings bridge.

Existing-site leasing is the core operating-leverage engine

A tower already has land, structure, power access, maintenance routines, and monitoring. A new tenant or equipment amendment can therefore add revenue at much lower incremental cost than building another site.

This is why colocations and amendments are central to tower cash flow margin, not just a revenue-growth line.

New leasing should not be confused with portfolio expansion

American Tower separates colocations and amendments from new-site tenant billings. SBA similarly describes organic site leasing growth as coming from new leases, amendments, and contractual escalators on the portfolio, while separately identifying revenue from acquired and newly built towers.

That boundary helps distinguish demand on the installed tower base from growth purchased or constructed through capital deployment. It also keeps organic tenant billings growth from being inflated by new-site additions.

Primary sources: American Tower second-quarter 2026 results and SBA Communications second-quarter 2026 Form 10-Q.

Part of the Wireless Tower Leasing Economics

Connects recurring tower tenant billings with existing-site leasing, contract escalators, churn, new-site contribution, accounting normalization, site-level cash margins, and recurring maintenance intensity.

Browse the full operating model in Company Analysis →
Where this concept fits
  • Existing-site leasing, escalators, and churnCurrent relationship
    Colocations and amendments add recurring billings to existing towers, contractual escalators lift rates on leases already in place, and churn removes billings through cancellations, non-renewals, or repricing. Core leasing activity and organic tenant billings growth summarize different issuer-defined views of that same operating engine.
    Colocation & Amendment BillingsCurrent conceptTower Rent EscalatorsTower Core Leasing ActivityOrganic Tower Billings GrowthTower Tenant Churn
  • Recurring billings, new sites, and accounting presentation
    Tenant billings capture recurring contractual lease economics, new-site tenant billings isolate the day-one contribution from constructed or acquired sites, and site-rental billings versus GAAP revenue separates the operating lease base from straight-line and other accounting effects.
    New-Site Tenant BillingsTower Billings vs. GAAP RevenueTower Tenant Billings
  • Site-level cash economics and reinvestment
    Tower cash flow margin shows the high site-level profitability of the leasing model after direct tower operating costs, while maintenance capex shows the recurring physical reinvestment needed to keep the installed infrastructure productive.
    Tower Cash Flow MarginTower Maintenance Capex

See It in Company Research

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Compare existing-site leasing demand

Compare new tenants and equipment amendments on the installed tower base separately from new-site construction and acquisitions.

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