405
Area code
OK
United States geographic area code, in service since 1947-01-01. Part of the 405/572 overlay complex — ten-digit dialing required.
Statusin service
Introduced1947-01-01
JurisdictionOK, US
Local dialing10D
Time zoneCentral
Last verified2026-09-17
Utilization 101% of assignable prefixes assigned
As of 09/17/2026
0%800 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 2001-01-03, most recent 2026-09-03.
Area codes serve rate-center geographies, not municipal boundaries. “OK” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | SOUTHWESTERN BELL | 237 | 29.6% |
| 02 | NEW CINGULAR WIRELESS PCS, LLC - IL | 102 | 12.8% |
| 03 | T-MOBILE USA, INC. | 87 | 10.9% |
| 04 | ONVOY, LLC - OK | 56 | 7% |
| 05 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - OK | 55 | 6.9% |
| 06 | COMCAST IP PHONE, LLC | 41 | 5.1% |
| 07 | LEVEL 3 COMMUNICATIONS, LLC - OK | 22 | 2.8% |
| 08 | VALOR TELECOM TX.LP-OK DBA WINDSTREAM COMM SW | 18 | 2.3% |
| 09 | PAETEC ITEL, LLC | 16 | 2% |
| 10 | PIONEER TEL. COOP., INC. | 14 | 1.8% |
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- 2020-03-04 NPA 572 to Overlay NPA 405 (Oklahoma)
- 1997-01-15 Declaration of Jeopardy Situation in NPA 405 (Oklahoma) jeopardy
- 1947-01-01Area code 405 entered service.
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2020-03-04 | PL-535 ↗ | NPA 572 to Overlay NPA 405 (Oklahoma) |