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US area code · Michigan

Area code 231

Where the 231 area code is, its overlay and how to dial a +1 231 number from anywhere.

CoversMuskegon, MichiganTime zoneEastern (ET)TypeGeographic
Quick answer

The 231 area code is in Muskegon, Michigan, United States (Eastern (ET)). To call from abroad: +1 231 555-0123.

StateMichigan
Main areaMuskegon
Time zoneEastern (ET)
TypeGeographic
10-digit dialingNot required
In service since11-Mar-1999

The 231 area code is a geographic North American Numbering Plan (NANP) code covering Muskegon, Michigan. It has been in service since 11-Mar-1999 and sits in the Eastern (ET) time zone.

How to dial a 231 number

From abroad+1 231 555-0123
Within the US / Canada1 231 555-0123

Cities in the 231 area code

A 231 number is usually in one of these places in Michigan — 2 counties.

Muskegon MuskegonNorton ShoresShelby Oceana

Other Michigan area codes

248269313517586616679734810906947989

Frequently asked questions

Where is the 231 area code?

The 231 area code is in Muskegon, Michigan, United States (Eastern (ET)).

Do I have to dial 10 digits for 231?

Local calls within 231 may use seven digits; ten-digit dialling always works.

How do I call a 231 number from another country?

Dial your exit code (or +), then 1, then 231, then the number: +1 231 555-0123.

Source: NANPA numbering plan. An area code covers a region, not a precise address — a 231 number does not pinpoint a street or ZIP code.

Missed a call from +1 231?

In the 30 days to September 24, 2026, 785 unwanted calls showing a 231 number were reported to the US Federal Trade Commission, 76% of them recorded messages or robocalls. That puts 231 at #80 of 670 area codes reported.

Other316
Reducing your debt (credit cards, mortgage, student loans)286
Calls pretending to be government, businesses, or family and friends45
Dropped call or no message45
Before you call back
  • If you do not know anyone in Michigan, do not call back: a genuine caller will leave a message or send a text.
  • Scammers fake the number shown on caller ID, so a 231 number can hide a caller anywhere in the world.
  • Never give a code received by text or a bank detail to an unknown caller. In the US, calls can be reported at reportfraud.ftc.gov.

Who issues +1 231 numbers

Phone companies hold blocks of numbers in each area code. The main holders in 231:

New Cingular Wireless PCS, LLC 72Michigan Bell Tel Co 72Frontier North, Inc. 52Onvoy, Llcv 49Telnet Worldwide, Inc. 43Cellco Partnership Dba Verizon Wireless 42

About 19.1% of the 596 prefixes in use belong to mobile carriers: a 231 number is often a cell phone, and it may have moved to another carrier since.

Sources: FTC Do Not Call reported calls (numbers as reported by consumers, not verified), NANPA central office code assignments.

All US area codes United States +1 Map of area code 231 — cities & rate centres