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: 378

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-378 A Plaistow NH PLSTNHMADS0  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      
603-378 0 Plaistow NH PLSTNHMADS0  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      
603-378 1 Plaistow NH MNCHNHCOX9Z  637E ONVOY, LLC - NH 122   2025-01-23   
603-378 2 Plaistow NH PLSTNHMADS0  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      
603-378 3 Plaistow NH   145J TERRA NOVA TELECOM INC. 122   2021-12-12   
603-378 5 Plaistow NH MNCHNHIE6MD  318J COMCAST IP PHONE, LLC 122   2016-11-07   
603-378 8 Plaistow NH MNCHNHCO23Z  073H TELNYX LLC 122   2022-12-23   
603-378 9 Plaistow NH PLSTNHMADS0  5113 CONSOLIDATED COMM OF NO. NEW ENGLAND-NH 122      

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

Sponsored by: Execulink Telecom

Like this site? We accept donations via PayPal.