Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 603 [Rate centres in NPA 603] [Dial plan for NPA 603]

NXX: 956

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-956 A Portsmouth NH MNCHNHCO18Z  197D VONAGE AMERICA LLC 122      
603-956 0 Portsmouth NH   939H COMMIO, LLC 122   2022-11-24   
603-956 1 Portsmouth NH   073H TELNYX LLC 122   2022-12-15   
603-956 2 Portsmouth NH   197D VONAGE AMERICA LLC 122   2022-09-23   
603-956 3 Portsmouth NH   637E ONVOY, LLC - NH 122   2022-09-29   
603-956 4 Portsmouth NH   637E ONVOY, LLC - NH 122   2022-09-29   
603-956 5 Portsmouth NH   637E ONVOY, LLC - NH 122   2022-12-23   
603-956 6 Portsmouth NH   637E ONVOY, LLC - NH 122   2023-08-20   
603-956 7 Portsmouth NH   637E ONVOY, LLC - NH 122   2023-05-08   
603-956 8 Portsmouth NH   8299 TELEPORT COMMUNICATIONS AMERICA, LLC - NH 122   2024-01-02   
603-956 9 Portsmouth NH   637E ONVOY, LLC - NH 122   2023-06-23   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

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