The California Public Utilities Commission (CPUC) has forecasted that the 818 area code (San Fernando Valley, California) will run out of telephone numbers in the third quarter of 2009 and has therefore announced an overlay with new area code 747; that is, as is the case with the old 310 and new 424 area codes, both area codes will exist in a single geographic area, with most new telephone numbers assigned receiving the new 747 area code.
Because an 818 and a 747 telephone number may therefore be in the same house or office building, ten-digit dialing (dialing the area code plus the number) will become mandatory in the 818 area code, effective April 18, 2009. The advantage of an overlay rather than a split is that any person or business with an 818 number will be able to keep that number, and no decision has to be made as to what geographic are retains the 818 area code and what area must adapt the new area code. Public hearings showed the public favored the overlay solution.
Cities in area code 818 include Agoura, Agoura Hills, Arleta, Calabasas, Canoga Park, Chatsworth, Encino, Glendale, Granada Hills, Hidden Hills, La Cañada Flintridge, Lake View Terrace, Mission Hills, North Hills, North Hollywood, Northridge, Pacoima, Panorama City, Reseda, San Fernando, Sherman Oaks, Studio City, Sunland, Sun Valley, Sylmar, Tarzana, Toluca Lake, Topanga, Tujunga, Universal City, Valley Village, Van Nuys, West Hills, Westlake Village, Winnetka, Woodland Hills, and of course "Media Capital of the World" Burbank.
More information: CPUC 818 Area Code Change Information