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: 840 [Rate centres in NPA 840] [Dial plan for NPA 840]

NXX: 287

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
840-287 A Marshall CA   649C ONVOY, LLC - CA 730   2026-02-02   
840-287 0 Marshall CA   649C ONVOY, LLC - CA 730   2026-02-02   
840-287 1 Marshall CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2026-02-20   
840-287 2 Marshall CA   649C ONVOY, LLC - CA 730   2026-03-14   

Last updated: Wed, 04 Mar 2026 03:00:52 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.