Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 857 [Rate centres in NPA 857] [Dial plan for NPA 857]

NXX: 431

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
857-431 A Boston MA   700J WAVENATION, LLC 128   2025-09-06   
857-431 0 Boston MA   700J WAVENATION, LLC 128   2025-09-06   
857-431 1 Boston MA   490J DISH WIRELESS, LLC 128   2026-03-05   
857-431 2 Boston MA   490J DISH WIRELESS, LLC 128   2026-01-12   

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

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