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: SNFCCASYOMD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
628-291 A Mill Valley CA 597F VOIP INNOVATIONS, LLC 722      
628-291 4 Mill Valley CA 597F VOIP INNOVATIONS, LLC 722   2026-06-14   

Last updated: Thu, 16 Jul 2026 02:21:55 UTC

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