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: 333

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
840-333 A Pomona CA LSANCAJWIMD  965H FRACTEL, LLC 730      
840-333 0 Pomona CA   649C ONVOY, LLC - CA 730   2021-07-30   
840-333 1 Pomona CA   649C ONVOY, LLC - CA 730   2021-07-30   
840-333 2 Pomona CA   649C ONVOY, LLC - CA 730   2021-07-30   
840-333 3 Pomona CA   965H FRACTEL, LLC 730   2021-02-25   
840-333 4 Pomona CA   965H FRACTEL, LLC 730   2021-02-25   
840-333 5 Pomona CA   649C ONVOY, LLC - CA 730   2021-07-30   
840-333 6 Pomona CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-09-30   
840-333 7 Pomona CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-07-30   
840-333 8 Pomona CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-07-30   
840-333 9 Pomona CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-07-30   

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.