Phone calls in parts of Alameda and Contra Costa counties are about to change.
State officials are introducing a new area code to replace the current 510 area code used in much of the East Bay.
Starting July 22, all new phone lines issued in the region will be assigned the 341 area code.
Existing phone numbers with the 510 area code will not be affected.
Beginning June 22, residents with a 510 phone number will have to start dialing the area code with every phone call, regardless of where the phone call is being made from.
The 510 area code includes parts of western Alameda and Contra Costa counties, which includes the cities of Alameda, Albany, Berkeley, El Cerrito, Emeryville, Fremont, Hayward, Hercules, Newark, Oakland, Piedmont, Pinole, Richmond, San Leandro, San Pablo and Union City.