When will the Oklahoma 918 / 539 Area Code Overlay change begin?
Beginning August 7, 2010, all customers with a 918 area code should begin dialing the area code for ALL calls. There will be a grace period, so if you forget and dial just seven digits during the grace period, your call will still be completed. Beginning March 5, 2011, all customers with a 918 area code must use the new dialing procedure for all calls. On or after this date, if you do not use the new dialing procedure, your call will not be completed, and a recording will instruct you to hang up and dial again. Beginning April 1, 2011, new telephone lines or services may be assigned numbers with the 539 area code. All customers with a 539 area code must dial the area code + telephone number on all calls or the call will not be completed.
