US Carrier IP Pools by Metro: AT&T, T-Mobile and Verizon Depth

USAProx runs its own modems, routers and phones in eight American metros, each with a physical SIM on AT&T, T-Mobile or Verizon. Customers regularly ask which carrier has the biggest IP pool, as if the answer were a single number per carrier. It is not. A carrier's pool is regional: the block of addresses a gateway can assign to SIMs attached in that area. Verizon in New York and Verizon in Phoenix are different pools with different depth and different habits, and the address you receive geolocates wherever the carrier's gateway says it does, which is not always where the modem physically sits. This guide goes through the pools carrier by carrier and metro by metro, in honest qualitative terms, and shows how to choose a line for a given job in a given city.

A carrier pool is a regional block, not a national one

When a SIM attaches to AT&T, T-Mobile or Verizon, the carrier's packet gateway for that region assigns it a public IPv4 address out of the block that gateway manages for that APN. That block is the pool. It is finite, it belongs to one carrier, and it serves one region. Behind it sits carrier grade NAT, so the address your proxy presents is the same address a large number of ordinary phones in the area are presenting at the same moment.

None of the three carriers hands a single SIM access to their whole national address space. Your line sees the share of the carrier that its gateway exposes, and when it rotates, it draws again from that same share. That is why the depth you can actually use is a per-line, per-metro property, and why a national headline count tells you nothing about the line you are buying.

Same carrier, different pool in every metro

Take Verizon. Its New York gateway serves one of the densest subscriber populations in the country, and the block it manages, and how busily it recycles addresses, reflects that. Its Phoenix gateway serves a different population, on different hardware, with a different block. A USAProx customer with a Verizon line in each city is on two unrelated pools that happen to share a carrier name. The same holds for AT&T and T-Mobile across New York, Los Angeles, Chicago, Houston, Phoenix, Miami, North Carolina and Boston.

This is the most common misunderstanding we correct in chat. A customer who had a great AT&T line in Miami assumes AT&T in Chicago will behave the same way. Sometimes it does. Often the Chicago block is deeper or shallower, stickier or fresher, simply because it is a different gateway under different load. Judge each carrier in each metro on its own, and expect the ranking of the three carriers to be different from one city to the next.

Where a pool geolocates: the gateway decides

The address a line gets is registered to the carrier, and the location that geolocation services attach to it comes from where the carrier's gateway announces the block, not from where our rack stands. In most of our metros that lines up with the city. Boston is the useful exception: our Boston hardware's Verizon addresses geolocate as Boston, while the AT&T addresses from the same rack geolocate as New York, because AT&T routes that region through a gateway announced there.

For a customer who needs a Boston address on a Boston line, that means choosing Verizon, and for a customer who wanted a New York address with a less crowded pool, the Boston AT&T line is a quiet way to get one. The lesson generalises: check where a line's addresses actually geolocate before you commit accounts to it, because the pool you are on is defined by the gateway, and the gateway sets the geography.

Depth versus stickiness, carrier by carrier

Two qualities matter, and they move independently. Depth is how many distinct addresses a line uncovers over weeks and months. Stickiness is how readily a rotation lands back on an address the line held in the last day, or how long an idle line keeps the same address. In our racks Verizon lines tend to hand out a fresh address readily on rotation. AT&T lines tend to be stickier and revisit addresses more often, which is a virtue for accounts that want a stable home and a nuisance for jobs that want novelty. T-Mobile varies more by metro than either of the others: fresh in one city, sticky in the next.

These are tendencies observed from operating the hardware, not fixed properties, and they shift as carriers rebalance gateways. Treat any exact count as depending on carrier, metro and how often you rotate. A quiet pool that returns the same address after a short detach is not a fault; nobody else claimed it in the seconds you were offline. If you wanted a fresh one, stay offline a little longer before re-attaching, or rotate again, and support can adjust the detach duration on a line.

Cadence changes the count, not the pool

Customers sometimes compare two lines by how many addresses each showed in a week, without noticing that one was rotated every few minutes and the other a few times a day. The heavily rotated line always shows the bigger list, on any pool. The fair comparison is yield: how many rotations produced an address the line had not held before. A shallow block rotated hard churns the same addresses; a deep block rotated gently still uncovers new ones.

As a rule of thumb, a single carrier line rotated many times a day tends to turn up a few hundred distinct addresses in its first week and low thousands over a quarter, with the fastest discovery early on and a slow but never-ending trickle after that. Rotation itself is under your control from the dashboard, a rotation link or the API, takes seconds, and can be as rare or as frequent as your job needs. It never manufactures addresses the gateway does not hold.

Picking a line per job and per metro

Once you separate depth from stickiness and stop reading raw counts, choosing a line is straightforward. Decide what the job needs from an address, then pick the carrier in the target metro whose current behaviour matches. Many USAProx customers run a small mix rather than one line, and because switching carrier or moving city is free, the first choice is not a commitment.

Whatever the mix, remember that sharing an address with many phones behind the carrier's NAT is not anonymity. Platforms attribute by account, device and behaviour. The value of a US carrier address is the trust attached to the carrier network and a consistent, believable geography per account, which is exactly why the metro and the gateway matter more than the size of anyone's headline pool.

• Aged accounts that need a stable home: a sticky-leaning line in the metro the account already lives in, rotated rarely
• Onboarding new accounts or verification work: a fresh-yielding line in the target metro, rotated per task
• Research and scraping across a region: a fresh-yielding line in each metro you need, rotated on a timer that matches your request volume
• Jobs that require a specific city to geolocate correctly: check the carrier's gateway geography first, as the Boston example shows

What to do next with USAProx

Pick the metro your job needs, run the line against the real target for a day, and keep your own list of the addresses you saw and where they geolocated. If the line is fresher or stickier than the job wants, do not tune the rotation timer first. Open the live chat on the site, tell us the city and what you are doing, and ask which carrier line there is currently rotating freshest, or which is holding addresses longest.

We can switch your proxy to a different carrier in the same metro or move it to any of our other seven cities, and both are free. Every line is a physical American SIM on hardware we own, so the change happens in our rack, on our schedule, and you keep a real US carrier address throughout.

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