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: 227 [Rate centres in NPA 227] [Dial plan for NPA 227]

NXX: 317

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
227-317 A Frederick MD   876D ONVOY, LLC - MD 240   2026-10-03   
227-317 0 Frederick MD   876D ONVOY, LLC - MD 240   2026-10-03   
227-317 8 Frederick MD   071F BANDWIDTH.COM CLEC, LLC - MD 240   2026-10-05   
227-317 9 Frederick MD   071F BANDWIDTH.COM CLEC, LLC - MD 240   2026-10-05   

Last updated: Tue, 01 Sep 2026 00:40:05 UTC

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