Diamond Bar, CA — rate center
- State
- California
- Active prefixes
- 31
- Carriers
- 14
- Pooled prefixes
- 22
- LATA
- 730
- Metro area
- Los Angeles-Long Beach-Anaheim, CA MSA
Phone numbers "from Diamond Bar" are, precisely speaking, numbers whose prefixes are anchored to the Diamond Bar rate center of California, under 840, 909.
NANPA records show 31 active prefixes here across 14 carriers. 22 prefixes participate in thousands-block pooling, so blocks of 1,000 numbers are shared between carriers.
The rate center belongs to the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area. Routing-wise it sits in LATA 730.
Multiple area codes over one rate center (840/909) is the overlay pattern: same geography, different first three digits.
As always with US numbering: a prefix anchored to Diamond Bar tells you where the block was issued. The person calling may have ported the number, moved away, or be spoofing it entirely — verify callers through independently found contact details.
Prefixes anchored to Diamond Bar
| Prefix | Code holder | Pooled |
|---|---|---|
| 909-274 | CHARTER IP ENABLED SERVICES, LLC | Yes |
| 909-323 | ONVOY, LLC - CA | Yes |
| 909-345 | BANDWIDTH.COM CLEC, LLC - CA | Yes |
| 909-348 | LEVEL 3 TELECOM OF CALIFORNIA, LP - CA | Yes |
| 909-378 | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | Yes |
| 909-396 | FRONTIER CALIFORNIA INC. | No |
| 909-444 | FRONTIER CALIFORNIA INC. | No |
| 909-468 | FRONTIER CALIFORNIA INC. | No |
| 909-551 | TWC IP ENABLED SERVICES, LLC | Yes |
| 909-569 | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | Yes |
| 909-594 | FRONTIER CALIFORNIA INC. | No |
| 909-595 | FRONTIER CALIFORNIA INC. | No |
| 909-598 | FRONTIER CALIFORNIA INC. | No |
| 909-610 | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - CA | Yes |
| 909-612 | FRONTIER CALIFORNIA INC. | Yes |
| 909-616 | NEW CINGULAR WIRELESS PCS, LLC | Yes |
| 909-655 | BANDWIDTH.COM CLEC, LLC - CA | Yes |
| 909-718 | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | Yes |
| 909-760 | ONVOY, LLC - CA | Yes |
| 909-839 | FRONTIER CALIFORNIA INC. | Yes |
| 909-859 | PACIFIC BELL (COMPETITIVE) | Yes |
| 909-860 | FRONTIER CALIFORNIA INC. | No |
| 909-861 | FRONTIER CALIFORNIA INC. | No |
| 909-869 | FRONTIER CALIFORNIA INC. | No |
| 909-895 | LEVEL 3 COMMUNICATIONS, LLC - CA | Yes |
| 909-914 | BANDWIDTH.COM CLEC, LLC - CA | Yes |
| 909-978 | U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS | Yes |
| 909-979 | FRONTIER CALIFORNIA INC. | Yes |
FAQ
What area code is Diamond Bar, CA?
Diamond Bar is served by 2 area codes — 840, 909 — which overlay the same territory.
How many prefixes does Diamond Bar have?
31 active NXX prefixes are anchored to this rate center in NANPA records, held by 14 carriers.
Is a call from a Diamond Bar prefix really from Diamond Bar?
Not necessarily. The prefix marks where the number block was issued; porting, VoIP and spoofing all detach calls from that geography.