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: 799

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
840-799 A Rialto CA LSANCAJWIMD  965H FRACTEL, LLC 730      
840-799 1 Rialto CA   939H COMMIO, LLC 730   2021-10-11   
840-799 2 Rialto CA   939H COMMIO, LLC 730   2021-10-11   
840-799 3 Rialto CA   939H COMMIO, LLC 730   2021-10-11   
840-799 4 Rialto CA   939H COMMIO, LLC 730   2021-10-11   
840-799 5 Rialto CA   939H COMMIO, LLC 730   2021-10-11   
840-799 6 Rialto CA   649C ONVOY, LLC - CA 730   2022-06-16   
840-799 7 Rialto CA   516J TON80 COMMUNICATIONS, LLC 730   2022-04-05   
840-799 8 Rialto CA   073H TELNYX LLC 730   2022-05-22   
840-799 9 Rialto CA   965H FRACTEL, LLC 730   2021-09-13   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.