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: 310

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
227-310 A Washington Zone 10 MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2026-04-25   
227-310 9 Washington Zone 10 MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2026-04-25   

Last updated: Wed, 04 Mar 2026 03:00:52 UTC

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