My Day Pass IP Shows Another City: What a 4G Address Reads As
Published
You buy a $4 day pass in Boston, paste the address into an IP checker, and it says New York. Or a Phoenix line comes back as a city on the far side of Arizona. The first thought is that you were given the wrong line. Almost always you were not. The address a 4G line shows to the world is assigned by the carrier's regional gateway, and the city a database attaches to it reflects where that gateway is, where the carrier registered the block, and what the database last learned, not where the modem is bolted to a rack. This article explains the gap, carrier by carrier, and tells you which fields to trust.
Two different things called location
The physical location of your line is simple: a modem with a SIM in one of our eight metro sites. The IP location is something else entirely. It is a guess made by a geolocation database about where the public address is used, based on registration records from the carrier, routing data and whatever hints the database has collected. For a home broadband address the guess is usually good. For a carrier address, which serves thousands of phones through a regional gateway, the guess lands wherever the gateway or the registration points.
So when a checker says New York for a Boston line, it is not reporting where the modem is. It is reporting where the carrier's gateway for that traffic is, or where the database thinks the block lives. Different databases can even disagree with each other about the same address.
How each carrier reads
T-Mobile is the most literal of the three. Its addresses most consistently geolocate to the metro the SIM is in, so a T-Mobile day pass in Houston usually reads as Houston. If you need the city itself to be right, T-Mobile is the safest pick.
Verizon is regional. A Verizon address can resolve to a hub city a few hundred miles away within the same part of the country, so a Phoenix line may read as another Arizona or south-western city. The state is almost always right; the city often is not. AT&T sits between the two, with one quirk we see every day: AT&T lines in our Boston rack exit through New York and read as New York, while Verizon lines in Boston read as Boston. If Boston specifically matters, buy Verizon there.
What to check before you write to support
Run through these four fields on any IP checker and you will know within a minute whether the line is doing what it should.
- Organisation or ASN: it should say AT&T Mobility (AS20057), T-Mobile USA (AS21928) or Verizon Wireless (AS22394, sometimes AS6167). This confirms the carrier.
- Connection type: mobile or cellular. This confirms you are on a carrier network rather than a datacenter.
- Country: United States. This is reliable on all three carriers.
- State: it should match the metro's state. This is reliable on all three carriers; the city underneath it is the only field that drifts.
When the city genuinely matters
Most sites make decisions at the country or state level: which prices to show, which store is nearest, whether a local section appears, whether a login looks plausible. For those, every carrier works. A few things key on the city, such as a store app choosing a default branch or a local-edition page. If your day depends on the city reading right, do three things: choose T-Mobile, rotate once or twice and pick the address whose city reads best, and remember that rotation keeps you in the same metro so the choice sticks until you rotate again.
You can also move the line for free to another metro at any time. If a Boston AT&T line reads as New York and you wanted New England specifically, moving to Boston on Verizon or buying a second $4 Verizon pass is the fix, and the remaining hours are preserved on a move.
Why we would rather tell you this up front
We could print 'Boston' on the checkout page and let you discover the AT&T quirk yourself. We prefer to say it here, on the carrier pages and in the dashboard, because the day pass is cheap enough that the honest version costs you nothing: buy a 4G day pass for $4, check the four fields, and if the city is wrong for your purpose, rotate, move or swap carrier. The address was never wrong; it just reads the way carrier addresses read.
Frequently asked
I bought Boston and the IP says New York. Did I get the wrong line?
If the carrier is AT&T, no. AT&T traffic from Boston exits through New York and reads as New York. Verizon in Boston reads as Boston.
Which carrier shows the correct city most often?
T-Mobile. Verizon is the most likely to show a regional hub a few hundred miles away. The state is right on all three.
Will rotating fix the city?
Sometimes. Each new address has its own database entry, so rotate once or twice and keep the one that reads best. The metro and carrier stay the same.
Do websites see the same city as the checker?
Only if they use the same database. Different sites use different databases and can disagree. The state and country are what almost all of them agree on.