Prefix 512-203 — Austin, TX
The 512-203 prefix belongs to area code 512 and is anchored to the Austin rate center (TX). In NANP terms, the prefix — or NXX — determines the rate center a number is billed against.
Austin is part of the Austin-Round Rock-San Marcos, TX Metropolitan Statistical Area. For routing purposes it sits in LATA 558. Numbers here keep Central time.
The assigned code holder is T-MOBILE USA, INC., operating company number 6529, assigned November 14, 2002. This is a pooled prefix — expect numbers within it to be split across more than one carrier in 1,000-number blocks.
Caller ID showing 512-203 is not proof the call came from Austin: spoofing and porting both detach numbers from their origin. To verify a caller, hang up and dial the organization's published number, and report suspicious calls to the FTC.
Neighboring prefixes
| Prefix | Rate center | Code holder |
|---|---|---|
| 512-200 | Austin | T-MOBILE USA, INC. |
| 512-201 | Austin | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX |
| 512-202 | Austin | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX |
| 512-204 | Austin | AMERICAN MESSAGING SERVICES, LLC |
| 512-205 | Austin | SPOK, INC. |
| 512-206 | Austin | SOUTHWESTERN BELL |
FAQ
Where is 512-203 located?
The prefix is assigned to the Austin rate center in TX, area code 512. It is part of the Austin-Round Rock-San Marcos, TX Metropolitan Statistical Area.
Which company owns 512-203 numbers?
T-MOBILE USA, INC. holds the code, but the prefix is pooled — individual thousands-blocks can be assigned to other carriers, and numbers may be ported to any provider.
Is a call from 512-203 safe to answer?
The prefix itself says nothing about the caller. Legitimate Austin businesses and spoofed robocalls can both display it. Never share personal data with an unverified inbound caller.