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: 815

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-815 A Durham NH MNCHNHCOX1Y  8299 TELEPORT COMMUNICATIONS AMERICA, LLC - NH 122      
603-815 0 Durham NH MNCHNHCOX1Y  8299 TELEPORT COMMUNICATIONS AMERICA, LLC - NH 122   2008-02-11   
603-815 1 Durham NH MNCHNHACAMD  6386 BELL ATLANTIC MOBILE, INC 122   2021-08-23   
603-815 2 Durham NH MNCHNHACAMD  6386 BELL ATLANTIC MOBILE, INC 122   2017-07-11   
603-815 3 Durham NH   6386 BELL ATLANTIC MOBILE, INC 122   2025-01-22   
603-815 4 Durham NH MNCHNHIE6MD  318J COMCAST IP PHONE, LLC 122   2015-01-12   
603-815 8 Durham NH MNCHNHACAMD  6386 BELL ATLANTIC MOBILE, INC 122   2023-09-19   
603-815 9 Durham NH MNCHNHCO23Z  073H TELNYX LLC 122   2022-11-07   

Last updated: Sat, 05 Apr 2025 03:03:23 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.