Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

Switch: ALBYCA11DS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
510-292 A Oakland: Berkeley DA CA 9740 PACIFIC BELL 722      
510-524 A Oakland: Berkeley DA CA 9740 PACIFIC BELL 722      
510-525 A Oakland: Berkeley DA CA 9740 PACIFIC BELL 722      
510-526 A Oakland: Berkeley DA CA 9740 PACIFIC BELL 722      
510-527 A Oakland: Berkeley DA CA 9740 PACIFIC BELL 722      
510-528 A Oakland: Berkeley DA CA 9740 PACIFIC BELL 722      
510-558 A Oakland: Berkeley DA CA 9740 PACIFIC BELL 722      
510-559 A Oakland: Berkeley DA CA 9740 PACIFIC BELL 722      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.