661
Area code
Statusin service
Introduced1999-02-13
JurisdictionCA, US
Local dialing7D
Time zonePacific
Last verified2026-09-17
Utilization 88.8% of assignable prefixes assigned
As of 09/17/2026
0%703 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 2001-02-07, most recent 2026-09-03.
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 | 145 | 20.6% |
| 02 | NEW CINGULAR WIRELESS PCS, LLC | 75 | 10.7% |
| 03 | T-MOBILE USA, INC. | 56 | 8% |
| 04 | ONVOY, LLC - CA | 50 | 7.1% |
| 05 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA | 49 | 7% |
| 06 | LEVEL 3 COMMUNICATIONS, LLC - CA | 35 | 5% |
| 07 | FRONTIER CALIFORNIA INC. | 29 | 4.1% |
| 08 | BANDWIDTH.COM CLEC, LLC - CA | 29 | 4.1% |
| 09 | 20 | 2.8% | |
| 10 | METROPCS NETWORKS, LLC | 19 | 2.7% |
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- 1999-02-13Area code 661 entered service (created from 805).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 1998-02-12 | PL-111 ↗ | NANP-Split of 805 (California) Numbering Plan Area (NPA) |