How are new area codes created? And what part of Minnesota could be next on the list?

MINNEAPOLIS — It's been a few decades since Minnesotans have dialed up one of these transitions. A new area code is coming for those who live in the 507.

Starting Aug. 30, the code 924 will join the 507 region.

What now takes a few taps of your finger at one point required several quick-moving hands. Operators connected callers via switchboard until the 1940s when the Bell Telephone Company automated the system using three-digit area codes.

In Minnesota, that meant you were either 612, which was the east side of the state south of Duluth, and 218 everywhere else. Those two codes activated in 1947 would get divided several times in the decades that followed.

The first change happened in 1954. That's when the 507 area code was added for southern Minnesota.

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Then came a rush of changes in the late 1990s. Phone numbers were running out quickly for the 612 area code due in large part to cellphones. Fax machines, pagers and modems also required new phone numbers.

The western portion of the 612 area became 320 in 1996. Two years later, St. Paul and surrounding areas became 651. Then in 2000, the 612 was divided again. Area codes 763 and 952 were added for suburbs north, west and south of Minneapolis except for a few neighboring cities like Richfield and St. Louis Park.

"Fourteen years ago, we got the first notice that 507 was getting exhausted," said Joseph Sullivan, commissioner for the Minnesota Public Utilities Commission.

Sullivan said the potential exhaustion of phone numbers in 507 became more apparent in 2020, leading to the process of implementing a new area code for the region.

Does the state have any say in what the three digits are for an area code? The short answer is no.

"They're assigned by the North American Numbering Plan Administrator (NANPA)," he said.

NANPA's formula for an area code is NXX. N, the first digit, can be numbers 2-9, while X can be 0-9.

There are 800 possible combinations using this formula, but several aren't available or are reserved for special purposes, like service codes such as 911.

NANPA also makes sure the new area code won't confuse callers where it is being implemented.

"For instance, 507 is the area code now. They would not do 570," said Sullivan.

When 924 is activated on Aug. 30, new phone numbers in the 507 could get the new area code. The addition of the new code was done using the overlay method. That means people can keep their existing 507 numbers, however, they'll have to dial the area code for all local calls. 

The other way to add a new area code is the split method. That's what happened to the 612 area code several times. The area was divided geographically. That meant some people, businesses and more had to have their phone numbers changed to accommodate the new area code. The benefit however is that local calls are still possible in those area codes without needing to dial the area code first. 

Which area code in the state might run out of phone numbers next?

"The 218 has been identified as being potentially exhausted by 2028," said Sullivan.

Click here to learn more about how area codes are created and their history.