608
Area code
WI
United States geographic area code, in service since 1955-01-01. Part of the 353/608 overlay complex — ten-digit dialing required.
Statusin service
Introduced1955-01-01
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 2001-01-15, most recent 2025-08-21.
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 | 80 | 10% |
| 02 | UNITED STATES CELLULAR - WI | 76 | 9.5% |
| 03 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI | 54 | 6.8% |
| 04 | FRONTIER NORTH INC. - WI | 53 | 6.6% |
| 05 | ONVOY, LLC - WI | 50 | 6.3% |
| 06 | NEW CINGULAR WIRELESS PCS, LLC - IL | 46 | 5.8% |
| 07 | T-MOBILE USA, INC. | 28 | 3.5% |
| 08 | CHARTER IP ENABLED SERVICES, LLC | 25 | 3.1% |
| 09 | BRIGHTSPEED OF CENTRAL WISCONSIN, LLC | 24 | 3% |
| 10 | LEVEL 3 COMMUNICATIONS, LLC - WI | 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- 2022-11-09 NPA 353 to Overlay NPA 608 (Wisconsin)
- 1955-01-01Area code 608 entered service.
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 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 |