Metro Detroit residents and businesses will soon need to adjust how they make local phone calls. Starting Oct. 7, all calls within the 313 area code must include the area code, ending traditional seven-digit dialing.
Once 10-digit dialing takes effect, any call made with just seven digits will not be completed. The change is the final step before the rollout of a new 679 overlay area code.
The 679 area code will become available beginning Nov. 7, 2025, but will only be assigned once all 313 numbers are exhausted — which state regulators now project to occur in the first quarter of 2028, “but the timing is subject to change due to telephone numbering demand,” the Michigan Public Service Commission (MPSC) said in a news release on Tuesday, Sept. 16.
The 313 area code currently serves Detroit, Allen Park, Dearborn, Dearborn Heights, Ecorse, the Grosse Pointes, Hamtramck, Highland Park, Inkster, Lincoln Park, Redford Township, River Rouge and Taylor. The new 679 area code will cover the same communities.
The new overlay code marks the third time the 313 area has been split. Its first split occurred in 1993 with the creation of the 810 area code, followed by a 1997 split when the 734 area code was introduced.
What residents need to know about 10-digit dialing and the 679 area code
According to the MPSC:
How to prepare to avoid disruptions
Before Oct. 7, residents should update contacts, speed dial settings, voicemail, call forwarding and any equipment currently set for seven-digit dialing to include the area code, according to the MPSC. This includes medical alert devices, security and alarm systems, fax machines, internet dial-up numbers, gates and other automated dialers.
Customers should also check business and personal materials, such as advertising, stationery, checks and ID tags, to ensure the area code is included when sharing their number.
Many systems already use 10-digit dialing, but older equipment may still rely on seven digits. Those unsure whether their devices need reprogramming should contact their service provider.
All updates should be completed before Oct. 7, 2025, to avoid disruptions.
Nour Rahal is a trending and breaking news reporter. Email her: nrahal@freepress.com. Follow her on Twitter @nrahal1.
This article originally appeared on Detroit Free Press: Metro Detroit switches to 10-digit dialing Oct. 7 as 679 area code nears rollout
Reporting by Nour Rahal, Detroit Free Press / Detroit Free Press
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