Local Calling Guide

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NPA: 603 [Rate centres in NPA 603] [Dial plan for NPA 603]

NXX: 503

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-503 A Lancaster NH MNCHNHACDS0  7778 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH 122      
603-503 0 Lancaster NH   6386 BELL ATLANTIC MOBILE, INC 122   2022-10-14   
603-503 4 Lancaster NH   6889 OMNIPOINT MIAMI E LICENSE, LLC 122   2025-11-28   
603-503 5 Lancaster NH   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 122   2018-11-05   
603-503 6 Lancaster NH   145J TERRA NOVA TELECOM INC. 122   2024-12-28   
603-503 9 Lancaster NH   7778 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - NH 122      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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