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: ELSBCA11DS0

Remotes:

Switch Switch name Switch type
CRCTCA02RS1  CROCKETT  5ER 
NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
510-222 A El Sobrante-Pinole CA 9740 PACIFIC BELL 722      
510-223 A El Sobrante-Pinole CA 9740 PACIFIC BELL 722      
510-243 A El Sobrante-Pinole CA 9740 PACIFIC BELL 722      
510-262 A El Sobrante-Pinole CA 9740 PACIFIC BELL 722      
510-669 A El Sobrante-Pinole CA 9740 PACIFIC BELL 722      
510-758 A El Sobrante-Pinole CA 9740 PACIFIC BELL 722      
510-765 A El Sobrante-Pinole CA 9740 PACIFIC BELL 722      

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

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.