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.

NPA: 424 [Rate centres in NPA 424] [Dial plan for NPA 424]

NXX: 557

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
424-557 A El Segundo CA   6006 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 730   2025-09-11   
424-557 7 El Segundo CA   145J TERRA NOVA TELECOM INC. 730   2025-09-12   
424-557 8 El Segundo CA   649C ONVOY, LLC - CA 730   2025-10-12   
424-557 9 El Segundo CA   649C ONVOY, LLC - CA 730   2026-05-30   

Last updated: Sun, 17 May 2026 03:26:51 UTC

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