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: 312

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
227-312 A Washington Zone 11 MD   876D ONVOY, LLC - MD 236   2026-09-28   
227-312 0 Washington Zone 11 MD   876D ONVOY, LLC - MD 236   2026-09-28   

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

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