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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Keystone, OK

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
918-243 A MNFROKXADS0  1982 CIMARRON TEL. CO. 538      

Last updated: Sun, 01 Jun 2025 02:18:11 UTC

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