Prefix 210-204 — San Antonio, TX

NANPA CO code assignment, current as of July 28, 2026.

The 210-204 prefix belongs to area code 210 and is anchored to the San Antonio rate center (TX). In NANP terms, the prefix — or NXX — determines the rate center a number is billed against.

San Antonio is part of the San Antonio-New Braunfels, TX Metropolitan Statistical Area. For routing purposes it sits in LATA 566. Numbers here keep Central time.

NANPA's central-office code records list T-MOBILE USA, INC. (OCN 6529) as the code holder, assigned March 10, 2004. Because 210-204 participates in thousands-block pooling, individual 1,000-number blocks may belong to other carriers than the code holder.

Caller ID showing 210-204 is not proof the call came from San Antonio: 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

FAQ

Where is 210-204 located?

The prefix is assigned to the San Antonio rate center in TX, area code 210. It is part of the San Antonio-New Braunfels, TX Metropolitan Statistical Area.

Which company owns 210-204 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 210-204 safe to answer?

The prefix itself says nothing about the caller. Legitimate San Antonio businesses and spoofed robocalls can both display it. Never share personal data with an unverified inbound caller.