Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
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NPA: 251 [Rate centres in NPA 251] [Dial plan for NPA 251]

NXX: 531

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
251-531 A Mount Vernon AL   321J HD CARRIER LLC 480   2025-10-17   
251-531 2 Mount Vernon AL   321J HD CARRIER LLC 480   2025-10-17   
251-531 3 Mount Vernon AL   321J HD CARRIER LLC 480   2025-10-17   
251-531 4 Mount Vernon AL   321J HD CARRIER LLC 480   2025-10-17   

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

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