The New 235 Area Code is Coming to the Missouri 573 Area Code Region

To ensure a continuing supply of telephone numbers, the Missouri Public Service Commission approved the addition of the new 235 area code to the geographic region served by the 573 area code. This process is known as an area code overlay.

What is an area code overlay?

An overlay is the addition of another area code (235) to the same geographic region as an existing area code (573). An overlay does not require customers to change their existing area code but does require using a new dialing procedure to complete local calls.

Who will be affected?

Anyone with a 573 area code telephone number will be affected. The 573 area code currently serves most of the eastern half of Missouri and includes the state capitol of Jefferson City. It serves communities such as Columbia, Cape Girardeau, Farmington, Fort Leonard Wood, Hannibal, Poplar Bluff, Rolla, Sikeston, and many other smaller communities.   The new 235 area code will serve the same geographic area currently served by the existing 573 area code.

Missouri area code 235 overlay map

What will be the new dialing procedure?

The new dialing procedure will require all calls in the 573 area code that are currently dialed with seven digits be dialed using area code + telephone number (10 digits). The same dialing procedure will apply to telephone numbers that are assigned in the new 235 area code.

When will the change begin?

Beginning August 26, 2023, you should begin dialing the area code + telephone number whenever you place a call. If you forget and dial just seven digits, your call will still be completed.

Beginning February 24, 2024, you must dial the area code + telephone number on all calls, including calls within the same area code. On and after this date, if you do not dial the area code + telephone number, your calls will not complete and a recording will instruct you to hang up and dial again, including the area code.

Beginning March 24, 2024, new telephone lines or services may be assigned numbers with the new 235 area code. If you have a 235 area code, you must dial the area code + telephone number or the call will not complete.

What will you need to do?

In addition to dialing the area code + telephone number for all local calls, all services, automatic dialing equipment, or other types of equipment that are programmed to dial a 7-digit number will need to be reprogrammed to include the area code. Some examples include life safety systems and medical monitoring devices, fire or burglar alarm and security systems or gates, PBXs, fax machines, Internet dial-up numbers, speed dialers, call forwarding settings, voicemail services and similar functions, etc. You should update your websites, personal and business stationery and checks, advertising materials, personal and pet ID tags and other such items 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 regardless of the number of digits dialed.
  • You can still dial just three digits to reach 911 and 988, as well as 211, 311, 411, 511, 611, 711 or 811, if currently available in your community.

Who may you contact with questions?

If you have any questions regarding this information, please call Metro by T-Mobile at 1-888-8METRO-8 or access the Missouri Public Service Commission at: