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: 231 [Rate centres in NPA 231] [Dial plan for NPA 231]

NXX: 522

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
231-522 A Luther MI GDRPMIBLX8Z  2550 123.NET, LLC 348      

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

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