ST. LOUIS – Officials have activated a new area code in St. Louis City and St. Louis County.

Earlier this year, the North American Numbering Plan Administrator (NANPA) announced the 314 area code would be exhausted by the third quarter of 2022, prompting the creation of an overlay plan with a new 557 area code.

The 314 area code was implemented in October 1947 and covered eastern Missouri from the Illinois border all the way to Jefferson City. The area was split in January 1996 with the addition of the 573 code. The 636 area code was introduced only two years later to cover St. Charles County and other suburban and rural areas.

Since then, the 314 code has served—but is not limited to—St. Louis City, Overland, Bridgeton, Florissant, Webster Groves, Creve Coeur, Kirkwood, and Sappington.

The Missouri Public Service Commission says the new 557 area code will be given to customers in the 314 region who request new service or additional phone lines. While the 557 area code has been activated, it might take a few weeks until service begins for numbers with that area code

The MPSC said existing phone customers with a 314 area code will not lose or have to change their phone numbers. The 557 code is not replacing the 314 code.

Whether calling a 557 or 314 number, callers will have to dial 10 digits for all local calls from here on out. Three-digit abbreviated dialing—such as 911, 211, 411, or 988—will not be affected by the new area code.