628
Area code
CA
United States geographic area code, in service since 2015-03-21. Part of the 415/628 overlay complex — ten-digit dialing required.
Statusin service
Introduced2015-03-21
JurisdictionCA, US
Local dialing1+10D
Time zonePacific
Last verified2026-09-17
Utilization 26.3% of assignable prefixes assigned
As of 09/17/2026
0%208 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 2014-09-29, most recent 2026-06-26.
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 | FRACTEL, LLC | 33 | 15.9% |
| 02 | ONVOY, LLC - CA | 32 | 15.4% |
| 03 | T-MOBILE USA, INC. | 28 | 13.5% |
| 04 | TELEPORT COMMUNICATIONS AMERICA, LLC - CA | 17 | 8.2% |
| 05 | BANDWIDTH.COM CLEC, LLC - CA | 13 | 6.3% |
| 06 | NEW CINGULAR WIRELESS PCS, LLC | 12 | 5.8% |
| 07 | MULTIPLE OCN LISTING | 9 | 4.3% |
| 08 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 9 | 4.3% |
| 09 | PEERLESS NETWORK OF CALIFORNIA, LLC - CA | 8 | 3.8% |
| 10 | LEVEL 3 COMMUNICATIONS, LLC - CA | 6 | 2.9% |
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- 2014-01-28 NPA 628 to Overlay NPA 415 (California)
- 2015-03-21Area code 628 entered service (created from 415).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2014-01-28 | PL-461 ↗ | NPA 628 to Overlay NPA 415 (California) |