279
Area code
CA
United States geographic area code, in service since 2018-03-10. Part of the 279/916 overlay complex — ten-digit dialing required.
Statusin service
Introduced2018-03-10
JurisdictionCA, US
Local dialing1+10D
Time zonePacific
Last verified2026-09-17
Utilization 20.5% of assignable prefixes assigned
As of 09/17/2026
0%162 of ~792 assignable NXX values (200–999 excl. N11)100%
Prefix-level assignment does not equal number-level exhaustion; thousands-block pooling extends capacity. First assignment on record 2018-01-17, most recent 2026-07-09.
Area codes serve rate-center geographies, not municipal boundaries. “CA” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | ONVOY, LLC - CA | 36 | 22.2% |
| 02 | FRACTEL, LLC | 36 | 22.2% |
| 03 | T-MOBILE USA, INC. | 15 | 9.3% |
| 04 | NEW CINGULAR WIRELESS PCS, LLC | 13 | 8% |
| 05 | MULTIPLE OCN LISTING | 9 | 5.6% |
| 06 | BANDWIDTH.COM CLEC, LLC - CA | 7 | 4.3% |
| 07 | 5 | 3.1% | |
| 08 | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 4 | 2.5% |
| 09 | COMMIO, LLC | 4 | 2.5% |
| 10 | TON80 COMMUNICATIONS, LLC | 3 | 1.9% |
Important: these are initial assignees from NANPA CO-code records — the carrier a prefix was originally assigned to. Because of number portability, the current serving carrier of any individual number may differ.
Change history
Recorded events for this NPA- 2017-03-08 NPA 279 to Overlay NPA 916 (California)
- 2018-03-10Area code 279 entered service (created from 916).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2017-03-08 | PL-502 ↗ | NPA 279 to Overlay NPA 916 (California) |