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: 855

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-855 A Alton NH ROCHNHWE4MD  314C IDT AMERICA, CORP. - NH 122      
603-855 2 Alton NH ROCHNHWE4MD  314C IDT AMERICA, CORP. - NH 122   2009-12-18   
603-855 5 Alton NH DOVRNHTHXEX  8299 TELEPORT COMMUNICATIONS AMERICA, LLC - NH 122   2020-04-05   
603-855 8 Alton NH   145J TERRA NOVA TELECOM INC. 122   2025-07-11   

Last updated: Fri, 25 Jul 2025 03:21:23 UTC

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