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: 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 7 Frederick MD   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 240   2026-10-09   
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: Sat, 10 Oct 2026 15:24:20 UTC

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