Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 240 [Rate centres in NPA 240] [Dial plan for NPA 240]

NXX: 857

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
240-857 A Washington Zone 5 MD LARLMDCC5MD  7591 LEVEL 3 TELECOM OF MARYLAND, LLC - MD 236      

Last updated: Thu, 16 Oct 2025 03:04:18 UTC

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