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: 603 [Rate centres in NPA 603] [Dial plan for NPA 603]

NXX: 839

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-839 A Farmington NH DOVRNHTHXMX  793K TWC IP ENABLED SERVICES, LLC 122      
603-839 1 Farmington NH ROCHNHWE4MD  314C IDT AMERICA, CORP. - NH 122   2008-04-18   
603-839 5 Farmington NH MNCHNHCO23Z  073H TELNYX LLC 122   2024-07-27   
603-839 6 Farmington NH DOVRNHTHXEX  8299 TELEPORT COMMUNICATIONS AMERICA, LLC - NH 122   2020-03-08   
603-839 9 Farmington NH DOVRNHTHXMX  793K TWC IP ENABLED SERVICES, LLC 122   2012-10-02   

Last updated: Sun, 27 Apr 2025 12:48:38 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.