353
Area code
WI
United States geographic area code, in service since 2023-09-15. Part of the 353/608 overlay complex — ten-digit dialing required.
Statusin service
Introduced2023-09-15
JurisdictionWI, US
Local dialing10D
Time zoneCentral
Last verified2026-09-17
Utilization 3.4% of assignable prefixes assigned
As of 09/17/2026
0%27 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 2025-08-21, most recent 2026-06-04.
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 | ONVOY, LLC - WI | 10 | 37% |
| 02 | MULTIPLE OCN LISTING | 9 | 33.3% |
| 03 | 5 | 18.5% | |
| 04 | WAVENATION, LLC | 1 | 3.7% |
| 05 | T-MOBILE USA, INC. | 1 | 3.7% |
| 06 | AHOI LLC | 1 | 3.7% |
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- 2022-11-09 NPA 353 to Overlay NPA 608 (Wisconsin)
- 2023-09-15Area code 353 entered service (created from 608).