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: 399

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-399 A Dundalk MD BLTOMDXIDS0  6050 GLOBAL CROSSING LOCAL SERVICES, INC. - MD 238      
443-399 0 Dundalk MD   876D ONVOY, LLC - MD 238      
443-399 1 Dundalk MD   876D ONVOY, LLC - MD 238      
443-399 2 Dundalk MD BLTMMDCH42Z  876D ONVOY, LLC - MD 238      
443-399 3 Dundalk MD BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238      
443-399 4 Dundalk MD BLTOMDXIDS0  6050 GLOBAL CROSSING LOCAL SERVICES, INC. - MD 238      
443-399 5 Dundalk MD BLTQMD01DS0  568G PEERLESS NETWORK OF MARYLAND, LLC 238      
443-399 6 Dundalk MD BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238      
443-399 7 Dundalk MD BLTMMDDN2MD  508J CENTURYLINK COMMUNICATIONS, LLC 238      
443-399 8 Dundalk MD BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238      
443-399 9 Dundalk MD   515J IP HORIZON LLC 238      

Last updated: Wed, 20 Nov 2024 21:20:06 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.