Who decided on new Detroit area code? Here’s what experts are saying on switch from 313 to 679

By Stone Andrews Last updated Jan 21, 2023

DETROIT – The state of Michigan is running out of 313 area codes and may be adding 679 into the mix in the Detroit area by late 2025.

But why 679? Who decided on that code? Local 4 sat down with an expert to find out.

Area code 313 is as recognizably Detroit as the skyline, but phone numbers aren’t infinite.

There are only so many numbers, but who decides when those run out and when a new area code is needed?

Local 4 sat down with Heidi Wayman of the North American Number Planning Administrations (NANPA) to find out.

“We’re neutral, so we’re just the facilitator,” said Wayman. “We filed a petition on behalf of the industry with the state, and then it’s in the state’s hands-on how they want to proceed. If they want to accept the application or petition that’s filed, ultimately that decision is up to them on the final outcome of what is ordered.”

There are a few ways an area code can change.

First, it can be split. This means any new numbers would be under a new area code when the old ones run out. This happened in Macomb County in 2001.

A split is not happening in Detroit. What’s happening to 313 is called an overlay. The new area code will operate in the same area as the old one.

There’s no real reason why numbers are chosen. It’s just first come, first serve as old area codes reach their limits.

“We have set aside numbers for the future area codes,” said Heidi Wayman. “They are set aside 10 years in advance, so we’re looking at things way out.”

NANPA’s job is a bit of a balancing act set up years in advance as populations grow.

Area code 313 is not expected to run out until 2025, but they let people know three years in advance so everyone has time to get ready.

For some, especially those with landlines, a new area code means a new way to dial. A switch from seven digits, or dialing locally without an area code, to dialing 10 digits with the area code.

“If you have a 313 number, you’re calling your neighbor, you could still dial seven digits,” Wayman said. ” When 679 is overlaid, most likely, you’re going to have to start dialing 313.”

Area code 313 is sticking around, it just isn’t going to be alone anymore.

The Detroit area code was one of the country’s first area codes assigned in 1947. Those first area codes, think New York, 212, Los Angeles, 213, and Chicago, 312, were set based on how long it would take to dial on a rotary phone.

The more people you had, or how important the city was, the easier it was to dial.

As for the new area code, it still needs to be formally approved, and if that happens, it will not go into effect until 2025.

A public hearing is set for March 9, 2023, from 1:30 pm to 3 pm at Wayne County Community College District’s downtown campus in the Frank Hayden Community Room #236, 1001 W. Fort Street in Detroit to take public comment on the proposal to add the 679 area code.

Related reading: Detroit’s 313 area code is expected to run out of unassigned numbers by late 2025