The New 557 Area Code is Coming to the Missouri 314 Area Code Region

To ensure a continuing supply of new telephone numbers, the Missouri Public Service Commission has approved an all-services area code overlay for the 314 area code region, which serves eastern Missouri including the communities of St. Louis, Overland, Bridgeton, Florissant, Webster Groves, Creve Coeur, Kirkwood and Sappington. The new 557 area code will serve the same geographic area currently served by the existing 314 area code.

What is an Area Code Overlay?

An overlay is the addition of another area code (557) to the same geographic region as an existing area code (314). The overlay does not require you to change your existing area code or phone number, or how you dial your calls. You will continue to dial the area code and phone number for all local calls, as you do today, within and between the 314 and new 557 area codes.

Who will be affected and when does the new 557 area code become effective?

Beginning August 12, 2022, customers in the 314 area code overlay region may be assigned a number in the new 557 area code when they request new service or an additional line. Customers receiving a 557 area code will be required to dial the area code and phone number for all local calls, just as customers with telephone numbers from the 314 area code do today.

What will you need to do?

Customers in the overlay region should:

  • Continue to dial 10 digits for all local calls, including calls within the same area code.
  • Continue to identify your telephone number as a 10-digit number, and include the area code when giving the number to friends, family, business associates, customers, etc.
  • Ensure that all services, automatic dialing equipment, or other types of equipment recognize the new 557 area code as a valid area code and continue to store or program telephone numbers as 10-digit numbers. Some examples are: stored telephone numbers in contact lists in wireless phones, PBXs, fax machines, Internet dial-up numbers, speed dialers, call forwarding settings, voicemail services, medical alert devices, safety alarm security systems and gates, ankle monitors and or other similar equipment.
  • Check items such as your website, personal and business stationery and printed checks, advertising materials, contact information, and your personal or pet ID tags to ensure the area code is included.

What will remain the same?

  • Your telephone number, including current area code, will not change.
  • The price of a call, coverage area, or other rates and services will not change due to the overlay.
  • What is a local call now will remain a local call.
  • You will continue to dial 10 digits for local calls within and between the overlay area codes, and 1+10 digits for long distance calls.
  • You can still dial just three digits to reach 911, as well as 211, 311, 411, 511, 611, 711 or 811 if those are currently available in your community.

Who may you contact with questions?

If you have any questions regarding information provided in this notice, please T-Mobile USA at 1-877-453-1304 for more information. You can also visit the Missouri Public Service Commission website at https://psc.mo.gov/Telecommunications/Telephone_NumbersLocal_Dialing