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: 342

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-342 A Hysham MT HYSHMTXCRS1  2251 RANGE TEL COOP INC 650      

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

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