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: SNJUCACL4MD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
341-223 A Oakland: Alameda DA CA 939H COMMIO, LLC 722      
341-243 A Hercules-Rodeo CA 939H COMMIO, LLC 722   2024-02-24   
369-203 A Bridgeville CA 939H COMMIO, LLC 722      
369-204 A Clearlake Oaks CA 939H COMMIO, LLC 722      
369-205 A Guerneville CA 939H COMMIO, LLC 722      
369-206 A Miranda CA 939H COMMIO, LLC 722      
369-207 A Trinidad CA 939H COMMIO, LLC 722      
369-214 A Santa Rosa CA 939H COMMIO, LLC 722   2024-02-24   
369-215 A Lower Lake CA 939H COMMIO, LLC 722   2024-03-03   
510-312 A Crockett CA 939H COMMIO, LLC 722      
628-292 A Belvedere CA 939H COMMIO, LLC 722      
628-293 A Nicasio CA 939H COMMIO, LLC 722      
628-867 A San Francisco: Central DA CA 939H COMMIO, LLC 722      
650-247 A Woodside CA 939H COMMIO, LLC 722   2024-03-03   
650-912 A Half Moon Bay CA 939H COMMIO, LLC 722      
669-337 A San Jose: South DA CA 939H COMMIO, LLC 722   2024-03-03   
831-280 A Aptos CA 939H COMMIO, LLC 722      
925-342 A Walnut Creek CA 939H COMMIO, LLC 722      
925-492 A Pittsburg CA 939H COMMIO, LLC 722      

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.