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.
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Switch: RIVSCAXFPS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
707-378 A Rio Vista CA 2308 CITIZENS TELECOM CA. DBA FRONTIER COM OF CA 722      
707-378 4 Rio Vista CA 2308 CITIZENS TELECOM CA. DBA FRONTIER COM OF CA 722   2010-09-17   

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

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