920
Area code
WI
United States geographic area code, in service since 1997-07-26. Part of the 274/920 overlay complex — ten-digit dialing required.
Statusin service
Introduced1997-07-26
JurisdictionWI, US
Local dialing10D
Time zoneCentral
Last verified2026-09-17
Utilization 100.9% of assignable prefixes assigned
As of 09/17/2026
0%799 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 2001-02-05, most recent 2026-09-03.
Area codes serve rate-center geographies, not municipal boundaries. “WI” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | WISCONSIN BELL INC | 141 | 17.6% |
| 02 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI | 62 | 7.8% |
| 03 | UNITED STATES CELLULAR - WI | 50 | 6.3% |
| 04 | LEVEL 3 COMMUNICATIONS, LLC - WI | 46 | 5.8% |
| 05 | NEW CINGULAR WIRELESS PCS, LLC - IL | 45 | 5.6% |
| 06 | FRONTIER NORTH INC. - WI | 42 | 5.3% |
| 07 | ONVOY, LLC - WI | 38 | 4.8% |
| 08 | NEW CELL DBA CELLCOM | 33 | 4.1% |
| 09 | T-MOBILE USA, INC. | 30 | 3.8% |
| 10 | TWC IP ENABLED SERVICES, LLC | 23 | 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- 2022-06-02 NPA 274 to Overlay NPA 920 (Wisconsin) – supersedes PL-586
- 1997-07-26Area code 920 entered service (created from 414).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2022-06-02 | PL-593 ↗ | NPA 274 to Overlay NPA 920 (Wisconsin) – supersedes PL-586 |
| 2022-03-16 | PL-586 ↗ | NPA 274 to Overlay NPA 920 (Wisconsin) |
| 2021-01-08 | PL-556 ↗ | Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Lifeline) – supersedes PL-544 |
| 2020-08-17 | PL-544 ↗ | Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Hotline |
| 2012-12-05 | PL-442 ↗ | NPA 274 to Overlay NPA 920 (Wisconsin) |
| 2010-12-22 | PL-417 ↗ | NPA 274 to Overlay NPA 920 (Wisconsin) |
| 2008-12-22 | PL-385 ↗ | NPA 274 to Overlay NPA 920 (Wisconsin) |
| 1997-02-18 | PL-040 ↗ | Reissuance of Notification of NANP-Split of 414 (Wisconsin) Numbering Plan Area (NPA) to Correct End Permissive Date |