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.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

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 PLSBWAXXX0X  6010 NEW CINGULAR WIRELESS PCS, LLC 674   2026-02-14   
425-581 0 Silver Lake WA STTLWAWBX7Z  006F BANDWIDTH.COM CLEC, LLC - WA 674   2026-02-16   
425-581 9 Silver Lake WA PLSBWAXXX0X  6010 NEW CINGULAR WIRELESS PCS, LLC 674   2026-02-14   

Last updated: Sat, 01 Aug 2026 03:19:33 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.