According to CITC, the Riyadh area code will change from 01 to 011 on May 13.
Dialing among fixed lines in the same city will remain the same however, the new digit must be added when dialing from mobiles to fixed lines, Arab News reported.
The new codes for other 5 regions will be implemented on August 18 and will be as follows:
Eastern Province 013
Southern Province 017