Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 443 [Rate centres in NPA 443] [Dial plan for NPA 443]

NXX: 577

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-577 A Glen Burnie MD CLMAMDJTDS0  2589 US LEC OF MARYLAND, INC. 238      
443-577 0 Glen Burnie MD   2589 US LEC OF MARYLAND, INC. 238      
443-577 1 Glen Burnie MD   2589 US LEC OF MARYLAND, INC. 238      
443-577 2 Glen Burnie MD   2589 US LEC OF MARYLAND, INC. 238      
443-577 3 Glen Burnie MD   2589 US LEC OF MARYLAND, INC. 238      
443-577 4 Glen Burnie MD   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2003-02-20   
443-577 5 Glen Burnie MD   2697 CTC COMMUNICATIONS CORP. - MD 238   2005-01-08   
443-577 6 Glen Burnie MD   6664 SPRINT SPECTRUM L.P. 238   2006-06-25   
443-577 7 Glen Burnie MD   2593 CORE COMMUNICATIONS, INC. - MD 238   2019-05-01   
443-577 8 Glen Burnie MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC DBA T-MOBILE USA 238   2016-07-14   
443-577 9 Glen Burnie MD   2589 US LEC OF MARYLAND, INC. 238      

Last updated: Sat, 31 Oct 2020 19:28:10 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.