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: 321

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
227-321 A Washington Zone 4 MD   876D ONVOY, LLC - MD 236   2026-10-26   
227-321 0 Washington Zone 4 MD   876D ONVOY, LLC - MD 236   2026-10-26   
227-321 1 Washington Zone 4 MD   071F BANDWIDTH.COM CLEC, LLC - MD 236   2026-11-08   
227-321 7 Washington Zone 4 MD   820C INTRADO COMMUNICATIONS, LLC 236   2026-10-27   

Last updated: Sun, 01 Nov 2026 02:11:49 UTC

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