231 Area CodeMuskegon, MI
Area code 231 covers Muskegon and nearby communities in Michigan, in the Eastern Time (ET) zone, home to about 241,000 people across 139 cities. It overlays 906, so the same region uses both and every local call needs all ten digits.
Overview
- Major City
- Muskegon
- State
- Michigan (MI)
- Timezone
- Eastern Time (ET)
- Current Time
- Overlay
- Yes – shares area with 906
Where is area code 231?
Area code 231 serves part of Muskegon, MI and the surrounding areas. It has a single overlay (906) that serves the same area.
Overview of the 231 Area Code
What is the 231 area code?
The 231 area code serves Muskegon, Michigan, alongside other established area codes. When you see a 231 number, it indicates a local number within this geographic area.
Why was area code 231 created?
The 231 area code was introduced as an overlay to add numbers in Muskegon once the existing area code 906 began to run out of available prefixes. It added a new supply of numbers without requiring current residents to change their existing digits.
Geographic Coverage of the 231 Area Code
The 231 area code serves Muskegon and surrounding areas in Michigan. It operates within the Eastern Time (ET) time zone. It complements the coverage of area code 906. This area code covers several key cities, including:
- Muskegon
- Norton Shores
- Traverse City
- Cadillac
- Muskegon Heights
- Big Rapids
Got a call from a 231 number? It came from Muskegon, MI. Since 231 overlays with 906, every local call in the region needs all ten digits to land on the right line. Inside 231, Muskegon holds about 15% of the population; the rest is split across 138 smaller cities.
Muskegon Area Codes Overview
Muskegon is served by multiple area codes, reflecting its telecommunications needs. The 231 area code operates alongside 906. Here are the area codes serving this region:
The introduction of the 231 area code helped prevent number exhaustion, ensuring a continuous supply of phone numbers across the geographic area.
What cities does area code 231 cover?
| City | State | Population | % of Area Code | % of City |
|---|---|---|---|---|
| Muskegon | MI | 37,287 | 0% | 100% |
| Norton Shores | MI | 25,070 | 0% | 100% |
| Traverse City | MI | 15,782 | 0% | 100% |
| Cadillac | MI | 10,521 | 0% | 100% |
| Muskegon Heights | MI | 9,806 | 0% | 100% |
| Big Rapids | MI | 8,565 | 0% | 100% |
| Ludington | MI | 7,577 | 0% | 100% |
| Manistee | MI | 6,241 | 0% | 100% |
| Petoskey | MI | 5,810 | 0% | 98% |
| Cheboygan | MI | 4,831 | 0% | 100% |
* Sources: Population – U.S. Census Bureau PEP, Vintage 2024 (SUB-IP-EST2024-POP). Area code assignments – NANPA CO Code data. See our data methodology.
Has area code 231 been reported for unwanted calls?
Yes – 820 unwanted-call complaints were reported to the FTC for numbers showing a 231 area code (May 29 – Jul 2, 2026).
- 78% robocalls
- ↑ 9% vs prior period
Most-reported subjects
- Other35%290
- Reducing your debt (credit cards, mortgage, student loans)32%264
- Calls pretending to be government, businesses, or family and friends5%43
* Caller ID is easily spoofed, so these figures reflect the number shown on caller ID, not the caller's true location – an area code alone never identifies a caller. The FTC does not verify the facts in these complaints. Source: FTC Do Not Call (DNC) Reported Calls Data, retrieved 2026-07-05.
Which prefixes and exchanges belong to area code 231?
56% assigned to a telco
- 75% Landline
- 25% Wireless
- 0% Unknown
| Prefix | Usage | Carrier |
|---|---|---|
| (231)201- | Wireless | New Cingular Wireless Pcs |
| (231)202- | Wireless | New Cingular Wireless Pcs |
| (231)203- | Wireless | New Cingular Wireless Pcs |
| (231)204- | Wireless | Usa Mobility Wireless |
| (231)205- | Landline | Telnet Worldwide |
| (231)206- | Wireless | Sprint Spectrum |
| (231)207- | Landline | Telnet Worldwide |
| (231)208- | Landline | Telnet Worldwide |
| (231)209- | Landline | Telnet Worldwide |
| (231)212- | Landline | Centurylink Communications |
Frequently Asked Questions about the 231 Area Code
Who called me from a 231 number?
A 231 number is assigned to Muskegon, Michigan, so a call may come from there. But caller ID is easy to fake, and scammers often spoof a local 231 code to look nearby, so a 231 number doesn't prove the caller is local. Recently, 820 unwanted-call complaints were reported to the FTC for numbers showing the 231 code (78% flagged as robocalls). If you don't recognize the number, let it go to voicemail; a real caller will leave a message.
Is 231 a scam area code?
No area code is a scam on its own. 231 is a normal, officially assigned code for Muskegon, Michigan. Spam callers spoof local codes to raise the odds you answer, so 231 on your caller ID says nothing about who is really calling. Recently, 820 unwanted-call complaints were reported to the FTC for numbers showing the 231 code (78% flagged as robocalls). Judge the call itself, not the area code.
Why do I keep getting calls from the 231 area code?
Repeated calls from different 231 numbers are usually spoofing: a robocaller rotates through 231 numbers so each call looks local and slips past simple blocks. Recently, 820 unwanted-call complaints were reported to the FTC for numbers showing the 231 code (78% flagged as robocalls). Blocking one number rarely helps; voicemail screening, your carrier spam filter, and the Do Not Call Registry work better.
Should I answer an unknown 231 number?
If you aren't expecting a 231 call, let it ring to voicemail. Legitimate callers leave a message, most robocallers hang up when no one picks up, and answering can mark your number as active and bring more calls.
How do I block calls from the 231 area code?
Block a single 231 number from your recent-calls list (iPhone: tap the number, then Block this Caller; Android: tap the number, then Block or report spam). To cut the volume, turn on Silence Unknown Callers on iPhone or spam protection on Android, enable spam filtering from your carrier, and register at DoNotCall.gov. Blocking the entire 231 code also stops legitimate local calls, so use it only as a last resort.
Where is area code 231?
Area code 231 covers Muskegon and the surrounding area in Michigan, spanning 139 cities with about 241,327 residents. It shares its area with overlay code 906.
Is 231 a real area code?
Yes. 231 is an active code in the North American Numbering Plan, assigned by NANPA and in service for Muskegon, Michigan. A real code can still show up on spoofed spam calls, so treat unknown 231 calls with normal caution.
What timezone is the 231 area code in?
The 231 area code is in the Eastern Time (ET). Because a number can be kept when someone moves or switches to VoIP, a specific 231 caller may not be in that zone.
How do I call a 231 number from abroad?
From outside the US, dial your country's exit code, then 1 (the US country code), then 231 and the seven-digit number. From a mobile phone you can usually just enter +1 231 followed by the number and let the phone add the exit code for you.