Area code 313 – Michigan
313 is one of the original area codes, in service across Michigan since 1947. 769 of its 786 number blocks are allocated – about 98% full. AT&T is the largest holder with 46.9% of blocks, ahead of T-Mobile at 18.3%. It shares its geography with overlay codes 679, so local calls take all ten digits. 672 FTC complaints named a 313 caller ID in the 33 days to 30 October 2026, putting it 146th of 422 codes with five or more complaints.
Who holds 313 number blocks
Share of the 769 assigned NXX blocks (97.8% of the 786 possible), across 35 carriers. This is share of number blocks, not of subscribers.
- AT&T46.9%
- T-Mobile20.3%
- Verizon10.3%
- Bandwidth3.6%
- Other CLEC / VoIP3.6%
- Onvoy3.3%
- American Messaging3.1%
- Lumen2.9%
- Windstream2%
- Spok1.7%
- Comcast1%
- Peerless0.5%
- Charter0.4%
- Vonage0.1%
- Dish0.1%
- VoIP Innovations0.1%
Spam complaints naming 313
FTC Do Not Call complaints where the caller ID was a 313 number, 28 Sep – 30 Oct 2026 (33 days). Caller IDs on spam calls are frequently spoofed, so these are complaints about the code, not calls proven to originate in it.
Rate centers in 313
NANPA allocates number blocks to rate centers and records their names abbreviated to ten characters, so these are NANPA's codes rather than place names – CHAMPAURBN is Champaign-Urbana, NWYRCYZN01 is a New York City zone. We show them unchanged instead of guessing at the full names. Showing the largest 5 of 6.
Timeline
- 1947 313 assigned in the original North American Numbering Plan.
More about 313
Separate pages for the questions that need their own answer: what time it is there, what the complaint data says, who holds the number blocks, and how the code compares with the one it shares its area with.
Frequently asked about 313
What state is area code 313?
Michigan. It covers the same area as 313/679.
Can I still get a 313 number?
Only from recycled stock. 769 of the 786 available blocks are already allocated, so new numbers in the area normally come from the overlay codes (313/679).
Is a call from 313 a scam?
Not by itself. 313 drew 672 FTC complaints in the 33 days to 30 October 2026, 146th of 422 ranked codes – mid-pack or lower. Spam callers spoof caller IDs, so the only useful check is the full number.
Which carrier owns 313 numbers?
AT&T holds the largest share of assigned number blocks at 46.9%. The rest is spread across 3 other carriers. This is share of number blocks, not of subscribers – people keep their numbers when they switch carriers.
Do I need to dial 10 digits in 313?
Yes – ten digits for local calls in 313, because it shares its area with another code.
Sources and verification
- NANPA – NPA Database (npa_report.csv), file date 11/01/2026, retrieved Nov 1, 2026
- NANPA – CO Code Assignment Records, All States (utilized), file updated 11/01/2026, retrieved Nov 1, 2026
- FTC – Do Not Call Reported Calls Data, 25 daily files 28 Sep – 30 Oct 2026, retrieved Nov 1, 2026
NANPA dialing note for this code: “10D”. Reviewed by the data desk. Spotted an error? Request a correction.