Residents in Michigan's 313 area code will switch to 10-digit dialing
If you have been used to dialing only seven digits for a telephone number when making local calls within the Detroit area, get ready to include the 313 area code as part of that process.
A new 10-digit dialing requirement begins Nov. 7, when the 679 area code will officially overlap with what is now solely a 313 district.
The Michigan Public Service Commission said in its announcement the reason for the update is that phone companies are maxing out the available numbers in the 313 area code.
This problem has happened before due to the proliferation of new customers, fax lines, dial-up internet, text services and personal cell phones outpacing the number of customers who are canceling or consolidating phone lines or moving out of the area.
Today's approach to assigning new phone numbers in a maxed-out area code is much different now than what was done decades ago.
Some Detroiters say despite the new area code coming to the area, 313 will always be Detroit.
"There's no other area code that you can relate to Detroit besides 313," said resident George Smith.
"You know we'll always be Motor City, we'll always be Motown, and we'll always be the 313. Even with the new things that are happening with the new area code coming around, we'll still always be the 313 that's like a legacy for us," said Clement Brown, owner of Three Thirteen. "Detroit pride wasn't super high, and people weren't really using the area code to represent the city, and so over the years, it's grown, and it's grown."
Splitting off the 313
Detroit's legacy 313 area code was created in 1947. At the time, it included a large part of eastern Michigan, according to the Telecom Michigan website.
The split-offs included:
- The 810 area code, which is generally north of the Metro Detroit area, split off in 1993.
- The 248 area code, another assigned area generally in Wayne County, split off in 1997.
- The 734 area code, which is generally Washtenaw and Monroe Counties, split off in 1997.
Overlay 679 with 313
The new 679 area code is called an overlay, as in overlapping with the current 313 area. The overlay numbering system is already in effect in many parts of the country such as in area code 248, which got an overlay number of 947 during 2000.
With an overlay, none of the existing 313 phone numbers will need to change.
Any new phone numbers issued after the 313 numbers run out in late 2025 will have a 679 area code instead of 313.
Why dial 10 digits?
A local call could have one of two area codes – 313 or 679. There will be no specific geographic assignment.
However, a number that is currently considered a local call for billing purposes will remain a local call for billing purposes.
As is done currently, all long-distance numbers should include 1 as a prefix before the rest of the numbers are dialed.
Permissive dialing
There is a run-up to the overlay taking effect called "permissive dialing."
Starting April 7, local calls can be made with either seven or 10-digit phone numbers. This is permissive dialing.
Starting Oct. 7, all local calls placed within the 313 area must be made with the assigned area code. Everyone who has a legacy 313 number will need to use 10-digit phone numbers to dial even another legacy 313 number or the newly assigned 679 number.
What you need to do
The Michigan Public Service Commission urges residents and businesses in the 313 area code to start including the area code when giving out phone numbers to friends, family, clients or customers, placing it on pet ID tags, or putting it on websites and advertising materials.
Phone customers also should check any software, automatic dialing equipment, speed dialing lists, call forwarding and life-safety systems to make sure that the area code is saved as the intended phone number.
"Please contact your medical alert or security provider if you are not sure whether your equipment needs to be reprogrammed to accommodate the upcoming change to 10-digit local dialing. Any needed reprogramming of alarm and home security equipment must be done between April 7, 2025, and Oct. 7, 2025," the commission said.
Emergency dispatch services via 911 will still be accessible with just those three digits, as 911 is a dedicated number across the country. Other dedicated, national three-digit lines such as 988 and 211 also will be accessible in the same way.
