Riverside, CA — rate center

NANPA rate center & CO code data, current as of July 28, 2026.

State
California
Area codes
909, 951
Active prefixes
155
Carriers
21
Pooled prefixes
86
LATA
730
Metro area
Riverside-San Bernardino-Ontario, CA MSA

In NANP numbering, Riverside, California is a rate center — the anchor point for local numbers. It is reached through 909, 951 (multiple area codes serve it).

The rate center currently carries 155 working prefixes, held by 21 different carriers. Pooling applies to 86 of them — individual thousands-blocks may belong to different companies.

The rate center belongs to the Riverside-San Bernardino-Ontario, CA Metropolitan Statistical Area. Routing-wise it sits in LATA 730.

Because 909, 951 all serve this territory, two Riverside numbers can look completely different while being neighbors — check the prefix, not just the area code.

Riverside ranks among the larger numbering localities in California: 155 prefixes mean over 1,550,000 assignable numbers anchored here.

A Riverside prefix on caller ID is a starting point, not proof of origin — numbers travel with their owners and displays can be spoofed. Use official callback numbers for anything sensitive.

Prefixes anchored to Riverside

Prefixes anchored to the Riverside rate center
PrefixCode holderPooled
909-209 AMERICAN MESSAGING SERVICES, LLC No
909-290 SPOK, INC. No
909-339 33 WIRELESS INC. No
909-412 SPOK, INC. No
909-416 SPOK, INC. No
909-540 33 WIRELESS INC. No
909-812 AMERICAN MESSAGING SERVICES, LLC No

FAQ

What area code is Riverside, CA?

Riverside is served by 2 area codes — 909, 951 — which overlay the same territory.

How many prefixes does Riverside have?

155 active NXX prefixes are anchored to this rate center in NANPA records, held by 21 carriers.

Is a call from a Riverside prefix really from Riverside?

Not necessarily. The prefix marks where the number block was issued; porting, VoIP and spoofing all detach calls from that geography.