Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 406 [Rate centres in NPA 406] [Dial plan for NPA 406]

NXX: 330

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-330 A Clinton MT MSSLMTEH4MD  792K CHARTER IP ENABLED SERVICES, LLC 648      
406-330 0 Clinton MT MSSLMTMACMD  6529 T-MOBILE USA, INC. 648   2024-09-23   
406-330 2 Clinton MT MSSLMTEH4MD  792K CHARTER IP ENABLED SERVICES, LLC 648   2006-06-03   
406-330 3 Clinton MT   145J TERRA NOVA TELECOM INC. 648   2025-10-06   

Last updated: Mon, 15 Sep 2025 02:24:40 UTC

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