CA
United States geographic area code, in service since 1947-01-01. Part of the 415/628 overlay complex — ten-digit dialing required.
Created 209. Created 408. Created 707. Created 510. Created 650. Created 628. Overlaid with 628 .
Prefix-level assignment does not equal number-level exhaustion; thousands-block pooling extends capacity. First assignment on record 2001-01-25, most recent 2026-07-22.
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 | PACIFIC BELL | 327 | 40.9% |
| 02 | NEW CINGULAR WIRELESS PCS, LLC | 67 | 8.4% |
| 03 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 48 | 6% |
| 04 | T-MOBILE USA, INC. | 45 | 5.6% |
| 05 | ONVOY, LLC - CA | 40 | 5% |
| 06 | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 36 | 4.5% |
| 07 | BANDWIDTH.COM CLEC, LLC - CA | 35 | 4.4% |
| 08 | LEVEL 3 COMMUNICATIONS, LLC - CA | 34 | 4.3% |
| 09 | METROPCS, INC. | 22 | 2.8% |
| 10 | SPOK, INC. | 21 | 2.6% |
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- 2014-01-28 NPA 628 to Overlay NPA 415 (California)
- 2011-06-21 NPA 415, 619, 650, 707 - Relief Plans Dismissed (California) other
- 1947-01-01Area code 415 entered service.
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2014-01-28 | PL-461 ↗ | NPA 628 to Overlay NPA 415 (California) |
| 2011-06-21 | PL-421 ↗ | NPA 415, 619, 650, 707 - Relief Plans Dismissed (California) |
| 2000-01-14 | PL-206 ↗ | Overlays Suspended in the 408, 415, 510, 650, 714 & 909 NPAs |
| 1999-08-26 | PL-191 ↗ | NANP- Overlay of 415 Numbering Plan Area (NPA) with 628 NPA - California |