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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NPA: 350 [Rate centres in NPA 350] [Dial plan for NPA 350]

NXX: 256

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
350-256 A Modesto CA   649C ONVOY, LLC - CA 738   2026-02-02   
350-256 0 Modesto CA   649C ONVOY, LLC - CA 738   2026-02-02   
350-256 1 Modesto CA   981E BANDWIDTH.COM CLEC, LLC - CA 738   2026-02-03   
350-256 8 Modesto CA   6006 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 738   2026-03-23   
350-256 9 Modesto CA   6006 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 738   2026-02-15   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

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