Area code 231

{{short description|Area code in Michigan, United States}} {{Use mdy dates|date=February 2026}} {{Use American English|date=February 2026}} thumb|right|Map of area code 231 in Michigan.

'''Area code 231''' is a telephone area code in the North American Numbering Plan (NANP) for the northwestern portion of the Lower Peninsula in the U.S. state of Michigan.

== History == Area code 231 was created in June 1999 by an area code split of area code 616, which had served the entire western half of the Lower Peninsula, extending west from the north-south line aligned with the Mackinac Bridge. 231 was carved out of the northern part. It is centered around the western half of the territory generally defined as Northern Michigan. It also includes Muskegon, which is almost universally counted as part of West Michigan.

==Service area== The numbering plan area includes the following communities: {{Div col|colwidth=20en|content=* Big Rapids * Boyne City * Cadillac * Charlevoix * Cheboygan * East Jordan * Elk Rapids * Harbor Springs * Hart * Kalkaska * Kingsley * Lake City * Ludington * Mackinaw City * Manistee * Muskegon * Newaygo * Norton Shores * Petoskey * Traverse City }}

==External links== * [http://www.nationalnanpa.com/pdf/pl-nanp-167.pdf Planning letter 167, which details 231's creation] (PDF) * {{Cite web |title=Michigan [map] {{!}} NANPA |url=https://www.nanpa.com/resources/area-code-map/michigan |access-date=2025-06-25 |website=NANPA}} *[http://www.nanpa.com/area_code_maps/display.html?mi Map of Michigan area codes] {{Webarchive|url=https://web.archive.org/web/20080630055917/http://www.nanpa.com/area_code_maps/display.html?mi |date=2008-06-30 }} at North American Numbering Plan Administration's website *[https://web.archive.org/web/20081017115948/http://www.areacodedownload.com/231/index.html List of exchanges from AreaCodeDownload.com, 231 Area Code]

{{Area code box | State = MI | This = 231 | N = 906 | W = Lake Michigan | E = 989 | S = 616}}

Category:Telecommunications-related introductions in 1999 231 231 Category:West Michigan Category:Northern Michigan