Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 301 [Rate centres in NPA 301] [Dial plan for NPA 301]

NXX: 558

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
301-558 A Washington Zone 13 MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2025-08-28   
301-558 5 Washington Zone 13 MD   876D ONVOY, LLC - MD 236   2025-08-29   
301-558 8 Washington Zone 13 MD   876D ONVOY, LLC - MD 236   2025-08-29   
301-558 9 Washington Zone 13 MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2025-08-28   

Last updated: Fri, 25 Jul 2025 03:21:23 UTC

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