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: 284

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
840-284 A Chino CA COVNCAXFX3Y  649C ONVOY, LLC - CA 730      
840-284 0 Chino CA   6529 T-MOBILE USA, INC. 730   2023-12-19   
840-284 1 Chino CA   6529 T-MOBILE USA, INC. 730   2023-12-19   
840-284 2 Chino CA   939H COMMIO, LLC 730   2024-01-28   
840-284 3 Chino CA   939H COMMIO, LLC 730   2024-01-28   
840-284 4 Chino CA   6529 T-MOBILE USA, INC. 730   2024-04-04   
840-284 5 Chino CA   6529 T-MOBILE USA, INC. 730   2024-04-04   
840-284 6 Chino CA   6006 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 730   2023-12-19   
840-284 7 Chino CA   6006 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 730   2023-12-20   
840-284 8 Chino CA   649C ONVOY, LLC - CA 730   2023-12-18   
840-284 9 Chino CA   6529 T-MOBILE USA, INC. 730   2024-07-16   

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

Sponsored by: BeeVox - Whitelabel Reseller Platform

Like this site? We accept donations via PayPal.