The Oklahoma Corporation Commission announced a few months ago that they were adding a new area code to the 405 calling area.
Starting April 24, all local calls within 405 will require ten-digit dialing (area code plus local number) on all calls.
The move to ten-digit dialing for local 405 area code calls is necessary to enable the addition of another area code for the area currently served only by 405. The additional area code (572) is needed to ensure there will be enough telephone numbers available for the area.
The changes will start on April 24 when mandatory ten digit dialing goes into effect for all calls in the 405 area code, to be followed on May 24 with the addition of the new 572 area code to the same area as the 405 area code.
The addition of the 572 area code will not change existing 405 telephone numbers. Also, there will be no change in the local call boundaries (local calls within the area will remain local calls, regardless of whether the number called is a 405 or 572 area code.)
The area currently served by the 405 area code is the second area in Oklahoma to institute 10 digit dialing. The first was the area served by the 918 area code, which is now served by both the 918 and 539 area codes. 539 was added in 2011.