Local Calling Guide

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

NXX: 397

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-397 A Durham NH MNCHNHIE6MD  318J COMCAST IP PHONE, LLC 122      
603-397 0 Durham NH   4017 LEVEL 3 COMMUNICATIONS, LLC - NH 122   2005-09-10   
603-397 1 Durham NH   829J PAETEC ITEL, LLC 122   2001-05-29   
603-397 2 Durham NH   6386 BELL ATLANTIC MOBILE, INC 122   2006-03-20   
603-397 3 Durham NH   4017 LEVEL 3 COMMUNICATIONS, LLC - NH 122   2004-09-04   
603-397 4 Durham NH   9827 OTEL TELEKOM, INC. - NH 122   2002-09-10   
603-397 5 Durham NH   318J COMCAST IP PHONE, LLC 122      
603-397 7 Durham NH   6386 BELL ATLANTIC MOBILE, INC 122   2004-12-03   
603-397 8 Durham NH   6386 BELL ATLANTIC MOBILE, INC 122   2012-10-12   
603-397 9 Durham NH   6386 BELL ATLANTIC MOBILE, INC 122   2008-11-03   

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

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