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: 583

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
424-583 A Torrance CA   649C ONVOY, LLC - CA 730   2026-10-18   
424-583 0 Torrance CA   649C ONVOY, LLC - CA 730   2026-10-18   

Last updated: Tue, 01 Sep 2026 00:40:05 UTC

Sponsored by: VoIP.ms

Like this site? We accept donations via PayPal.