SAVANNAH — Ten-digit dialing is coming to coastal and Middle Georgia this year.

Customers in the 912 and 478 area codes will have to start dialing the area code as well as the seven-digit phone number to complete local calls, enabling a new suicide prevention hotline.

Beginning April 24, customers can begin dialing 10 digits in the 912 area code, which includes Savannah, coastal and southeast Georgia, and the 478 area code, which includes Macon and Middle Georgia. If a customer only dials seven digits, a call will still go through.

Starting Oct. 24, 10 digits will be mandatory and a call won't be completed without the area code.

Somos Inc., which administers the North American area code plan, made the announcement last week.

The two Georgia regions are among 82 area codes nationwide making room for the 988 National Suicide Prevention Lifeline, which begins operation in July 2022. Because those 82 area codes use 988 for the first three numbers of some seven-digit phone numbers, the Federal Communications Commission ordered 10-digit dialing. Otherwise phones won't recognize when someone is trying to call the 988 suicide hotline.

Somos said people should reprogram medical alert devices, security and other systems.

Customers around Atlanta, Augusta and Columbus have long dialed 10 digits because their regions have multiple area codes.