Area codes 918 and 539 are telephone area codes serving Tulsa and northeast Oklahoma. Besides Tulsa, these area codes cover cities such as Bartlesville, Broken Arrow, Claremore, Gore, Jenks, McAlester, Muskogee, Okmulgee, Pryor, Sapulpa, Tahlequah, and northeastern Oklahoma.
Area code 918 was created in 1953 as a split from area code 405. Area code 539 was created as an overlay for 918. It became active on April 1, 2011 (although 539 numbers could have been assigned for activation before that date). Mandatory ten-digit dialing became effective on March 5, 2011. It is the first overlay in Oklahoma.[1][2]
The other area codes for Oklahoma are 405 and 572, which cover the Oklahoma City Metropolitan Area in central Oklahoma, and 580, which covers northern, western, and southern Oklahoma areas outside of the OKC metro.