Prefix 210-237 — San Antonio, TX

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

Area code
210
Prefix (NXX)
237
Rate center
San Antonio
State
Texas
Time zone
Central
Code holder
LEVEL 3 OF TELECOM OF TEXAS, LLC - TX
OCN
8434
Pooled
Yes (thousands-block pooling)
Assigned
2004-06-24
LATA
566

The 210-237 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 LEVEL 3 OF TELECOM OF TEXAS, LLC - TX (OCN 8434) as the code holder, assigned June 24, 2004. Because 210-237 participates in thousands-block pooling, individual 1,000-number blocks may belong to other carriers than the code holder.

Caller ID showing 210-237 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

Prefixes adjacent to 210-237
PrefixRate centerCode holder
210-234 San Antonio MCIMETRO ACCESS TRANSMISSION SERVICES LLC
210-235 San Antonio SOUTHWESTERN BELL
210-236 San Antonio TELEPORT COMMUNICATIONS AMERICA, LLC - TX
210-238 San Antonio CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX
210-239 San Antonio FOREMOST TELECOMMUNICATIONS CORPORATION - TX
210-240 San Antonio NEW CINGULAR WIRELESS PCS, LLC - IL

FAQ

Where is 210-237 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 210-237 numbers?

LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 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 210-237 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.