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: BYPKCA11RS1

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
805-528 A San Luis Obispo CA 9740 PACIFIC BELL 740      
805-534 A San Luis Obispo CA 9740 PACIFIC BELL 740      
805-534 0 San Luis Obispo CA 9740 PACIFIC BELL 740      
805-534 1 San Luis Obispo CA 9740 PACIFIC BELL 740      
805-534 9 San Luis Obispo CA 9740 PACIFIC BELL 740      

Last updated: Thu, 20 Nov 2025 13:34:34 UTC

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