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: 425 [Rate centres in NPA 425] [Dial plan for NPA 425]

NXX: 581

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
425-581 A Silver Lake WA   6010 NEW CINGULAR WIRELESS PCS, LLC 674   2026-02-14   
425-581 0 Silver Lake WA   006F BANDWIDTH.COM CLEC, LLC - WA 674   2026-02-16   
425-581 9 Silver Lake WA   6010 NEW CINGULAR WIRELESS PCS, LLC 674   2026-02-14   

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

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