Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 531 [Rate centres in NPA 531] [Dial plan for NPA 531]

NXX: 428

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
531-428 A Allen NE   7421 AT&T - LOCAL 644   2025-11-07   
531-428 9 Allen NE   7421 AT&T - LOCAL 644   2025-11-07   

Last updated: Sun, 07 Dec 2025 22:02:11 UTC

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