Area code

WI

United States geographic area code, in service since 2023-05-05. Part of the 274/920 overlay complex — ten-digit dialing required.

Split from 920. Overlaid with 920 .

Statusin service

Introduced2023-05-05

JurisdictionWI, US

Local dialing10D

Time zoneCentral

Last verified2026-09-17

Utilization 5.4% of assignable prefixes assigned As of 09/17/2026

0%43 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 2024-10-11, most recent 2026-06-17.

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

Largest initial assignees in area code 274
Rank	Assignee	Prefixes	Share
01	MULTIPLE OCN LISTING	9	20.9%
02	T-MOBILE USA, INC.	7	16.3%
03	ONVOY, LLC - WI	7	16.3%
04		5	11.6%
05	METROPCS, INC.	4	9.3%
06	ONVOY SPECTRUM, LLC	2	4.7%
07	NEW CINGULAR WIRELESS PCS, LLC - IL	2	4.7%
08	WISCONSIN RSA #10 LIMITED PARTNERSHIP	1	2.3%
09	WAVENATION, LLC	1	2.3%
10	TERRA NOVA TELECOM INC.	1	2.3%

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 overlay
2023-05-05Area code 274 entered service (created from 920).

Planning letters & orders

Primary documents

NANPA planning letters for area code 274
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)
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)

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