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: 666

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
840-666 A Fontana CA LSANCAJWIMD  965H FRACTEL, LLC 730      
840-666 0 Fontana CA RVSDCALBCM4  6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-04-08   
840-666 1 Fontana CA LSANCAJW7MD  939H COMMIO, LLC 730   2021-09-16   
840-666 2 Fontana CA LSANCAJW7MD  939H COMMIO, LLC 730   2021-09-16   
840-666 3 Fontana CA LSANCAJW7MD  939H COMMIO, LLC 730   2021-09-16   
840-666 4 Fontana CA LSANCAJW7MD  939H COMMIO, LLC 730   2021-09-16   
840-666 5 Fontana CA RVSDCALBCM4  6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-03-31   
840-666 6 Fontana CA LSANCAJWIMD  965H FRACTEL, LLC 730   2021-02-25   
840-666 7 Fontana CA RVSDCALBCM4  6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-03-31   
840-666 8 Fontana CA RVSDCAYAGT1  6529 T-MOBILE USA, INC. 730   2021-03-29   
840-666 9 Fontana CA RVSDCAYAGT1  6529 T-MOBILE USA, INC. 730   2021-03-29   

Last updated: Fri, 22 Mar 2024 03:02:44 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.