| General Information about Area Code 231 | |
|---|---|
| Country | United States |
| State / Province / Territory | Michigan |
| Major City | Muskegon |
| Time Zone | Eastern (UTC-05:00) |
| Prefix | Primary City | County | Phone Type |
|---|---|---|---|
| 231-571 | Muskegon | Muskegon | Landline |
| 231-635 | Mackinaw City | Cheboygan | Landline |
| 231-398 | Manistee | Manistee | Landline |
| 231-667 | Marion | Osceola | Wireless |
| 231-514 | Cadillac | Wexford | Wireless |
| 231-214 | Tustin | Osceola | Landline |
| 231-894 | Whitehall | Muskegon | Landline |
| 231-438 | Manistee | Manistee | Landline |
| 231-450 | Hesperia | Oceana | Landline |
| 231-652 | Newaygo | Newaygo | Landline |
| 231-362 | Kaleva | Manistee | Landline |
| 231-420 | Cheboygan | Cheboygan | Wireless |
| 231-208 | Boyne Falls | Charlevoix | Landline |
| 231-898 | Branch | Mason | Landline |
| 231-201 | Barryton | Mecosta | Wireless |
| 231-728 | Muskegon | Muskegon | Landline |
| 231-219 | Merritt | Missaukee | Landline |
| 231-777 | Muskegon | Muskegon | Landline |
| 231-805 | Kaleva | Manistee | Landline |
| 231-946 | Traverse City | Grand Traverse | Landline |