Search numbers reported to the U.S. Federal Commissions beginning with area code 231
Area code 231 belongs to MICHIGAN, UNITED STATES. It is a General Purpose Code which was placed in service on 1999-06-05.
| Type | General Purpose Code |
| Use | Geograpic |
| Location | MICHIGAN |
| Country | UNITED STATES |
| Service Date | 1999-06-05 |
| Service |