Michigan wants to add 679 area code, says Detroit area running out of 313 phone numbers
(CBS DETROIT) - The Detroit area is projected to run out of phone numbers with the 313 area code in the third quarter of 2025, according to the North American Numbering Plan Administrator (NANPA), which administers numbering plans in the United States.
In response, the Michigan Public Service Commission will hold a public hearing in Detroit on March 9 at the Wayne County Community District's downtown campus (Frank Hayden Community Room No. 236, 1001 W. Fort Street) to propose adding a 679 overlay.
This comes two months after NANPA filed a petition with MPSC to implement the overlay.
Officials predict there will be little to no numbers available within the 313 area code, which covers Detroit, its enclaves Hamtramck, Highland Park and the suburbs of Allen Park, Dearborn, Dearborn Heights, Ecorse, the Grosse Pointes, Inkster, Lincoln Park, Redford Township, River Rouge and Taylor.
If implemented, 679 will cover the same area, and will not change the existing phone numbers using 313. However, the 679 overlay will require callers to include the area code for local calls within and between the two area codes. Those calls will be billed as local.
Some devices, including auto dialing equipment, medical devices and home security systems will need to be reprogrammed.
"The Michigan Telecommunications Act grants the MPSC, which provides regulatory support for telecommunications providers, the authority to approve or reject area code changes in Michigan," read the press release. "The new area code would be phased into use, with dates to be determined, should the MPSC approve the overlay."
The 313 area code was assigned to Michigan in 1947 and was one of the original in NANPA. It initially served Southeast Michigan, including Flint and part of the state Thumb. It split back in 1993, creating the 810 area code and then again in 1997 when the 734 area code was created.
According to the petition, the 679 overlay was implemented more than 20 years ago.
"While the Order contains implementation instructions to the Industry, many factors such as customer education, dialing plan best practices, and technical milestones have changed in the two decades since the Order was approved," read the petition.
The NANPA proposes it will notify MPSC within 12 months when the 313 area code will exhaust, and the overlay will be implemented at least six months before the exhaust.