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: 597

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-597 A Lyme NH MNCHNHACDS0  7778 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH 122      
603-597 1 Lyme NH MNCHNHCOX9Z  637E ONVOY, LLC - NH 122   2023-08-20   
603-597 2 Lyme NH   145J TERRA NOVA TELECOM INC. 122   2023-11-11   
603-597 3 Lyme NH MNCHNHAC7MD  145J TERRA NOVA TELECOM INC. 122   2024-10-12   
603-597 9 Lyme NH MNCHNHACDS0  7778 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH 122      

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

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