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: CMTNCA01DS1

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
310-537 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
310-605 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
310-631 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
310-632 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
310-635 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
310-638 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
310-639 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
310-761 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
310-900 A Compton: Compton DA CA 9740 PACIFIC BELL 730      
323-636 A Los Angeles: DA 06 CA 9740 PACIFIC BELL 730      

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

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