Located in the Central (GMT -06:00) time zone. Area code 713 serves the state of Texas. This area code was assigned on January 1st, 1947. On January 1st, 1947 it went into service. 713 is a General Purpose Code. 713 service area does overlap with 281 346 832 area codes. Dialing pattern for local calls within the same NPA (area code) is 10D.