Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 227 [Rate centres in NPA 227] [Dial plan for NPA 227]

NXX: 666

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
227-666 A Frederick MD CMLDMDCMEMD  876D ONVOY, LLC - MD 240   2026-02-17   
227-666 0 Frederick MD CMLDMDCMEMD  876D ONVOY, LLC - MD 240   2026-02-17   
227-666 1 Frederick MD HGTWMDHGDMD  071F BANDWIDTH.COM CLEC, LLC - MD 240   2026-06-06   
227-666 5 Frederick MD MNRVMDMOXFX  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 240   2026-06-01   
227-666 6 Frederick MD CMLDMDCMEMD  876D ONVOY, LLC - MD 240   2026-02-17   
227-666 7 Frederick MD MNRVMDMOXFX  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 240   2026-06-01   
227-666 8 Frederick MD HGTWMDHGDMD  071F BANDWIDTH.COM CLEC, LLC - MD 240   2026-07-13   
227-666 9 Frederick MD CMLDMDCMEMD  876D ONVOY, LLC - MD 240   2026-06-13   

Last updated: Thu, 16 Jul 2026 02:21:55 UTC

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