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: 620

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
603-620 A Merrimack NH MNCHNHCOX4Z  6290 UNITED STATES CELLULAR - NH 122      
603-620 0 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 1 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 2 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 3 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 4 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 5 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 6 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 7 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 8 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      
603-620 9 Merrimack NH   6290 UNITED STATES CELLULAR - NH 122      

Last updated: Sat, 21 Mar 2026 23:53:39 UTC

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