Fiber Net Additions: Measuring Broadband Subscriber Growth

Fiber net additions measure the net increase or decrease in fiber broadband customer connections during a period.

A simplified formulation is:

1Fiber Net Additions
2≈ New Fiber Connections
3- Fiber Disconnects
4± Issuer-Defined Adjustments

The metric measures realized subscriber growth. It does not measure network footprint by itself.

Fiber net additions are not locations passed

A carrier can expand fiber availability without immediately adding a customer at every location.

1Fiber Locations Passed
2-> Addressable network footprint
3
4Fiber Net Additions
5-> Change in connected customers

AT&T's 2026 disclosures illustrate the distinction clearly. The company separately reported millions of fiber locations reached and hundreds of thousands of quarterly fiber net additions.

A growing footprint creates a larger addressable base, but take-up depends on sales execution, competition, pricing, migration from legacy products, and local market maturity.

Net additions are not ending connections

Ending fiber connections can change because of more than ordinary period net adds.

A useful bridge is:

1Ending Fiber Connections
2≈ Beginning Fiber Connections
3+ Organic Fiber Net Additions
4+ Acquired Connections
5- Divested Connections
6± Base Adjustments

T-Mobile's 2025 filing separately identified fiber customers acquired through Metronet and Lumos and also disclosed organic fiber net customer additions. Verizon's 2026 reporting changed materially after the Frontier acquisition expanded its fiber base.

That is why acquisition-driven base growth should not be silently labeled organic fiber net additions.

Fiber and fixed wireless solve similar customer needs but are different operating assets

Fixed Wireless Access Net Additions measure subscriber growth over a wireless broadband network. Fiber net additions use a physical fiber connection.

Both may compete for household broadband demand, but the economics differ in:

• construction capital;
• network capacity;
• installation requirements;
• incremental customer cost;
• service speeds and consistency;
• geographic reach; and
• long-run maintenance.

An issuer's total broadband growth can therefore hide a major mix shift between fiber and fixed wireless.

Strong net additions do not reveal penetration by themselves

Suppose a carrier adds 300,000 fiber customers in a quarter. That number may look strong, but interpretation depends on how many serviceable locations exist and how quickly the footprint is expanding.

A mature 10-million-location footprint and a newly built 30-million-location footprint can produce the same net additions with very different penetration dynamics.

The more complete investor view considers:

1Fiber Growth
2= Footprint Expansion
3+ Penetration of Existing Footprint
4- Disconnects
5± Acquisitions / Migrations

This is an analytical bridge, not a standardized accounting identity.

Consumer and business scope can differ

AT&T's 2026 operating data separately reports AT&T Fiber and Business Fiber, and its combined fiber net-add figure includes both. Other issuers may report consumer-only or product-specific populations.

Preserve the scope before comparing carriers.

Filing examples

AT&T reported 367,000 total consumer and business fiber net additions in the second quarter of 2026 while separately reporting more than 38 million fiber locations reached. T-Mobile disclosed fiber net customer additions separately from acquired fiber customer bases in 2025. Verizon began reporting a broader fiber broadband connection base after completing the Frontier acquisition in 2026.

Sources:

• AT&T second-quarter 2026 selected operating data
• AT&T second-quarter 2026 Form 10-Q
• T-Mobile US 2025 Form 10-K
• Verizon first-quarter 2026 Form 10-Q

Bottom line

Fiber net additions measure the net change in connected fiber customers, not fiber locations passed, total broadband growth, or acquisition-driven base expansion. Preserve consumer/business scope, footprint changes, acquisitions, migrations, and disconnect methodology before comparing carriers.

Explore more topics in the Financial Research Encyclopedia.