Missouri Public Service Commission

JEFFERSON CITY---The Missouri Public Service Commission, the North American Numbering Plan Administrator (NANPA) and the telecommunications industry remind customers to continue preparing for a new area code (235) in the current 573 area code in Missouri. As part of that process, customers should prepare for 10-digit local dialing.

The 235 area code will be added as an overlay to the 573 region. An overlay is the addition of another area code (235) to the same geographic region served by an existing area code (573). An overlay does not require customers to change their existing area code, but does require customers to dial the area code to complete local calls.

“Customers are reminded that the 573 area code is not going away and if they have a telephone number with the 573 area code, they will not lose or have to change their telephone number,” said Public Service Commission Chairman Scott Rupp. “An overlay is a more efficient and less disruptive way to alleviate the exhaustion of available telephone numbers which is occuring in the 573 area code.”

A six-month permissive dialing period will begin on August 26, 2023, to give consumers adequate time to adjust to the dialing changes. During this period, local calls can be made with either 7 or 10 digits, and all calls that are local will continue to be local even though you dial 10 digits.

Beginning February 24, 2024, all local calls made within the 573 area code must be placed using 10 digits (area code + the 7-digit telephone number). On and after that date, calls placed using just 7 digits will not be completed.

Starting on March 24, 2024, new telephone lines or services may be assigned numbers using the new 235 area code.

Key facts for consumers to know about the upcoming 573/235 area code overlay are:

Remember to identify your telephone number as a 10-digit number and include the area code when giving the number to friends, family, business associates and customers.

In addition to the permissive dialing period, customers should ensure all services, automatic dialing equipment, applications, software, or other types of equipment are reprogrammed to dial 10 digits if they are programmed to dial just 7 digits, and recognize the new 235 area code as a valid area code. Examples include life-safety systems, fax machines, Internet dial-up numbers, gates, ankle monitors, speed dialers, mobile phone contact lists, call forwarding settings, voicemail services, and similar functions. Be sure to check your business stationery, advertising materials, personal checks, and your personal or pet ID tags to ensure the area code is included in your telephone number.

Important safety and security equipment, such as medical alert devices, and alarm and security systems must be programmed to use 10-digit dialing. Many systems operate on 10-digit dialing by default, but some older equipment may still use 7 digits. Please contact your medical alert or security provider if you are not sure whether your equipment needs to be reprogrammed to accommodate the upcoming change to 10-digit local dialing. Any needed reprogramming of alarm and home security equipment must be done between August 26, 2023 and February 24, 2024.

The 573 area code serves communities such as, but not limited to, Jefferson City, Columbia, Rolla, Cape Girardeau, Poplar Bluff, Sikeston, Mexico, Hannibal, Camdenton, Waynesville, Farmington and Caruthersville.

For additional information, please visit the Missouri Public Service Commission at https://psc.mo.gov/Telecommunications/Telephone_NumbersLocal_Dialing or contact your local telephone service provider.

-30-