AUSTIN (June 29, 2012)--Regulators have approved an additional area code for Central Texas that will require callers to dial all 10 phone digits.

The Texas Public Utility Commission decision means the Austin area next July will have 737 and the current 512 as area codes.

PUC officials, who approved the new area code Thursday, say the 10-digit dialing will be phased in starting in December.

Authorities say the additional area code is needed to ensure that the 512 area code doesn’t run out of phone numbers.

New phone numbers could be assigned either area code.