Area code

MI

United States geographic area code, in service since 1997-05-10. Part of the 248/947 overlay complex — ten-digit dialing required.

Split from 810. Created 947. Overlaid with 947 .

Statusin service

Introduced1997-05-10

JurisdictionMI, US

Local dialing10D

Time zoneEastern

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 2001-01-25, most recent 2025-12-16.

Area codes serve rate-center geographies, not municipal boundaries. “MI” identifies the jurisdiction, not an exact city footprint.

Top assignees

Ranked by assigned prefixes · initial assignee ≠ current carrier

Largest initial assignees in area code 248
Rank	Assignee	Prefixes	Share
01	MICHIGAN BELL TEL CO	251	31.4%
02	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI	72	9%
03	NEW CINGULAR WIRELESS PCS, LLC - IL	66	8.3%
04	MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MI	62	7.8%
05	LEVEL 3 COMMUNICATIONS, LLC - MI	58	7.3%
06	METROPCS, INC.	49	6.1%
07	PAETEC ITEL, LLC	42	5.3%
08	TELEPORT COMMUNICATIONS AMERICA, LLC - MI	36	4.5%
09	OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC	35	4.4%
10	AMERICAN MESSAGING SERVICES, LLC	19	2.4%

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

2001-06-07 New NPA 947 to Overlay NPA 248 (Michigan) overlay
1997-05-10Area code 248 entered service (created from 810).

Planning letters & orders

Primary documents

NANPA planning letters for area code 248
Date	Document	Subject
2002-03-29	PL-320 ↗	Mandatory Dialing Postponed - 248/947 NPA Overlay (Michigan)
2001-06-07	PL-283 ↗	New NPA 947 to Overlay NPA 248 (Michigan)
2000-04-24	PL-227 ↗	Suspension of Relief in the 248, 313 and 734 NPAs (Michigan)
2000-02-01	PL-209 ↗	NPA 947 to Overlay NPA 248 / NPA 679 to Overlay NPA 313 / NPA 278 to Overlay NPA 734 (Michigan)
1996-10-08	PL-012 ↗	NANP-Split of 810 (Michigan) Numbering Plan Area (NPA)

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