Area Code 231: Muskegon, Michigan
231 is a telephone area code serving Michigan, including Muskegon, Traverse City. It is part of the North American Numbering Plan and is dialed with the country code +1.
Numbers beginning with 231 are located in Michigan, United States (NANP region: West). The code covers Muskegon, Traverse City.
How to Dial Area Code 231
| Calling from | What to dial |
|---|---|
| Anywhere in the US or Canada | 1 231 XXX-XXXX (10-digit dialing: 231 + 7-digit number) |
| Local call inside the same area code | 7-digit number in most areas; 10 digits where an overlay code is active |
| From the UK or Europe | 00 1 231 XXX XXXX |
| From Australia | 0011 1 231 XXX XXXX |
| From a mobile phone anywhere | +1 231 XXX XXXX |
Whatever country you are calling from, the + symbol replaces the exit code. Save the contact as +1 231 XXXXXXX and it will dial correctly from any phone in the world.
Time Zone for Area Code 231
Calls to a 231 number ring in the America/Detroit time zone, standard offset UTC-05:00. Daylight saving time applies here, so the offset moves forward one hour from March to November.
Note: the four Upper Peninsula counties bordering Wisconsin use Central time, one hour behind.
Cities and Communities Served by 231
The following places fall inside the 231 calling area:
Other Area Codes in Michigan
These codes also serve Michigan. Area codes are assigned by the North American Numbering Plan Administration (NANPA).
| Area Code | Cities / Coverage |
|---|---|
| 248 | Troy, Pontiac |
| 269 | Kalamazoo, Battle Creek |
| 313 | Detroit |
| 517 | Lansing, Jackson |
| 586 | Warren, Sterling Heights |
| 616 | Grand Rapids |
| 734 | Ann Arbor |
| 810 | Flint |
| 906 | Upper Peninsula |
| 947 | Oakland County (overlay) |
| 989 | Saginaw, Midland |
See all 12 area codes in Michigan →
Frequently Asked Questions
Where is area code 231?
Area code 231 is in Michigan, United States. It covers Muskegon, Traverse City.
What time zone is area code 231 in?
Area code 231 rings in the America/Detroit time zone (UTC-05:00 standard).
Do I need to dial 1 before area code 231?
Yes, for a long-distance call inside the US and Canada you dial 1 first, then 231, then the seven-digit number. The 1 is the North American long-distance trunk prefix — it is not the country code. From outside North America you dial your exit code then 1 then 231.
Is area code 231 toll-free?
No. 231 is a standard geographic area code, so normal long-distance rates apply unless your plan includes them. Toll-free NANP codes are 800, 833, 844, 855, 866, 877 and 888.