JEFFERSON CITY, Mo. – In February 2022, the North American Numbering Plan Administrator informed the Missouri Public Service Commission of the need for a new area code in the current 573 region due to an increase in residential and commercial phone numbers.

The 573 area code was implemented in January 1996 to split away from the 314 code. It runs from the Missouri Bootheel, around the St. Louis region (314 and 636 codes), and up to the northeast beyond Hannibal and Quincy. The biggest cities in the current 573 area code are Columbia, Jefferson City, Rolla, and Cape Girardeau.

A new 235 area code will be given to customers in the 573 region who request new service or additional phone lines. This is known as an overlay.

To be clear, the 235 code is not replacing the 573 code. The chairman of the Missouri Public Service Commission said existing customers with a 573 area code will not lose or have to change their phone number.

Instead, customers in the 573 region will have to dial 10 digits when the 235 area code is activated.

Beginning Saturday, Aug. 26, customers with a 573 area code will have what’s known as a “permissive dialing period,” in which local calls can be made with either seven or 10 digits. This is being done to get people used to dialing with the area code.

On Feb. 24, 2024, all local calls in the 573 region must be made using 10 digits (area code plus the seven-digit telephone number). On March 24, 2024, all new telephone lines and services will be assigned the 235 area code.

The Missouri Public Service Commission says the price of a call, coverage area, and other rates and services will not change with the 235 overlay.

Using three digits to reach 911 or 988 services will remain unaffected.