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   876D ONVOY, LLC - MD 240   2026-02-17   
227-666 0 Frederick MD   876D ONVOY, LLC - MD 240   2026-02-17   
227-666 6 Frederick MD   876D ONVOY, LLC - MD 240   2026-02-17   

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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