Prefix 314-203 — Saint Louis, MO

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

The 314-203 prefix belongs to area code 314 and is anchored to the Saint Louis rate center (MO). In NANP terms, the prefix — or NXX — determines the rate center a number is billed against.

Saint Louis is part of the St. Louis, MO-IL Metropolitan Statistical Area. For routing purposes it sits in LATA 520. Numbers here keep Central time.

Code-holder of record: T-MOBILE USA, INC. (OCN 6529), assigned April 19, 2013. The prefix is pooled: its ten thousands-blocks can be shared among several carriers, so different 314-203 numbers may be served by different companies.

Caller ID showing 314-203 is not proof the call came from Saint Louis: 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 314-203 located?

The prefix is assigned to the Saint Louis rate center in MO, area code 314. It is part of the St. Louis, MO-IL Metropolitan Statistical Area.

Which company owns 314-203 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 314-203 safe to answer?

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