Area code 231 was created in June 1999 as a split from area code 616. 231 is essentially the northern half of the old 616 area code. 616 previously covered the entire western half of the state of Michigan, extending west from the north-south line aligned with the Mackinac Bridge.

The new 231’s southern boundary closely follows the county lines between Muskegon County and Ottawa County and Kent County and Montcalm County.

Among the Michigan cities it serves are Big Rapids, Cadillac, Grant, Ludington, Muskegon, Petoskey, and Traverse City.