10-digit dialing required in Detroit as 679 joins iconic 313 area code

Starting Oct. 7, Detroit residents must use 10-digit dialing for all local calls
Providers will begin issuing the 679 area code on Nov.7 as the 313 area code is expected to run out
Current 313 numbers and call rates will not change. The 679 code is expected to serve Detroit and nearby suburbs for decades

Starting Tuesday, Detroit residents will need to dial all 10 digits, including the area code, for local calls, even if they’re just to neighbors across the street.

The shift comes as the state prepares to introduce a new 679 area code for Detroit, since the supply of 313 numbers is nearly exhausted.

In March, the Michigan Public Service Commission introduced a six-month transition period to encourage callers to get used to the change. After Oct. 7, calls made with only seven digits will no longer go through.

Phone providers will begin issuing 679 numbers on Nov. 7. The new area code will serve Detroit and surrounding suburbs, including Allen Park, Dearborn, Dearborn Heights, Ecorse, the Grosse Pointes, Hamtramck, Highland Park, Inkster, Lincoln Park, Redford Township, River Rouge and Taylor.

Individuals who already have the 313 area code will not need to change their current phone number, and rates will not change due to the new area code, according to the Michigan Public Service Commission.

Related:

The MPSC recommends that individuals update any devices, systems, or software that currently use seven-digit dialing and review business materials, ads, personal checks, etc for themselves or their pets to make sure phone numbers include the area code.

For cell phone users within the 313 area code, that means double-checking local contacts to make sure you’ve saved all 10 digits.

Code 679

The 679 area code, known as an “overlay,” is the third change to the 313 region. The first occurred in 1993 with the creation of the 810 area code, which covers major cities including Flint, Lapeer, Port Huron, Brighton and Fenton. The second was the 734 area code in 1997, which covers metro Detroit cities Livonia and Westland, in addition to Ann Arbor and Ypsilanti.

The MPSC initially approved adding another area code to cover the area in 2001 but the effort was delayed. The MPSC had a hearing in 2023 after it was projected that the 313 area code would run out of assigned phone numbers towards the end of 2025.

Southeast Michigan was first assigned the 313 area code in 1947, and the prefix has become so ingrained in Detroit culture that the city celebrates 313 Day every March 13.

The North American Numbering Plan Administrator, which administers the numbering plan for 20 North American countries, now estimates that 313 phone numbers will be exhausted by the fourth quarter of 2027, but that date could move again as demand changes.

The 679 area code should provide enough numbers for the region for about 46 years, according to the administrator.