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: 556

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-556 A Laconia NH MNCHNHCOX8Z  4017 LEVEL 3 COMMUNICATIONS, LLC - NH 122      
603-556 0 Laconia NH MNCHNHCOCM1  5562 METROPCS, INC. 122   2003-06-04   
603-556 1 Laconia NH MNCHNHCOCM1  5562 METROPCS, INC. 122   2003-06-04   
603-556 2 Laconia NH   6889 OMNIPOINT MIAMI E LICENSE, LLC 122   2003-06-04   
603-556 3 Laconia NH MNCHNHCOX9Z  637E ONVOY, LLC - NH 122   2021-08-02   
603-556 4 Laconia NH MNCHNHCOX8Z  4017 LEVEL 3 COMMUNICATIONS, LLC - NH 122      
603-556 5 Laconia NH MNCHNHCOX9Z  637E ONVOY, LLC - NH 122   2023-02-23   
603-556 7 Laconia NH MNCHNHCOX8Z  4017 LEVEL 3 COMMUNICATIONS, LLC - NH 122   2005-07-15   
603-556 8 Laconia NH MNCHNHCOX8Z  4017 LEVEL 3 COMMUNICATIONS, LLC - NH 122   2005-07-15   
603-556 9 Laconia NH ROCHNHWE4MD  314C IDT AMERICA, CORP. - NH 122   2010-08-08   

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

Sponsored by: BeeVox - Whitelabel Reseller Platform

Like this site? We accept donations via PayPal.