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: 523

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-523 A Canaan NH CANNNHYARS1  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      
603-523 2 Canaan NH MNCHNHIE6MD  318J COMCAST IP PHONE, LLC 122   2007-01-30   
603-523 3 Canaan NH CANNNHYARS1  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      
603-523 4 Canaan NH CANNNHYARS1  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      
603-523 7 Canaan NH CANNNHYARS1  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      
603-523 8 Canaan NH CANNNHYARS1  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      
603-523 9 Canaan NH CANNNHYARS1  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      

Last updated: Wed, 04 Mar 2026 03:00:52 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.