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: 840

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
240-840 A Frederick MD FRDRMDFRXPX  624H ONVOY SPECTRUM, LLC 240      
240-840 0 Frederick MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 240   2018-09-20   
240-840 1 Frederick MD   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 240   2018-09-25   
240-840 2 Frederick MD   551G NUSO, LLC 240   2018-11-07   
240-840 3 Frederick MD   551G NUSO, LLC 240   2018-11-07   
240-840 4 Frederick MD   551G NUSO, LLC 240   2018-11-07   
240-840 5 Frederick MD   551G NUSO, LLC 240   2018-11-07   
240-840 6 Frederick MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 240   2018-10-22   
240-840 7 Frederick MD   5562 METROPCS, INC. 240   2019-07-11   
240-840 8 Frederick MD   624H ONVOY SPECTRUM, LLC 240   2018-07-30   
240-840 9 Frederick MD   551G NUSO, LLC 240   2018-10-14   

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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