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: 831

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
240-831 A Frederick MD CMLDMDCMEMD  876D ONVOY, LLC - MD 240      
240-831 0 Frederick MD   5562 METROPCS, INC. 240   2018-06-18   
240-831 1 Frederick MD   6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 240   2018-07-09   
240-831 2 Frederick MD   5562 METROPCS, INC. 240   2018-07-01   
240-831 3 Frederick MD   551G NUSO, LLC 240   2018-11-07   
240-831 4 Frederick MD   318J COMCAST IP PHONE, LLC 240   2018-06-16   
240-831 5 Frederick MD   876D ONVOY, LLC - MD 240   2016-05-26   
240-831 6 Frederick MD   876D ONVOY, LLC - MD 240   2016-05-26   
240-831 7 Frederick MD   876D ONVOY, LLC - MD 240   2016-05-26   
240-831 8 Frederick MD   876D ONVOY, LLC - MD 240   2016-05-26   
240-831 9 Frederick MD   551G NUSO, LLC 240   2018-07-23   

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

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