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: 393

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-393 A Columbia MD BLTOMDXIDS0  6050 GLOBAL CROSSING LOCAL SERVICES, INC. - MD 238      
443-393 0 Columbia MD BLTOMDXIDS0  6050 GLOBAL CROSSING LOCAL SERVICES, INC. - MD 238      
443-393 1 Columbia MD BLTOMDXIDS0  6050 GLOBAL CROSSING LOCAL SERVICES, INC. - MD 238      
443-393 2 Columbia MD BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2005-09-10   
443-393 3 Columbia MD BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2005-09-10   
443-393 4 Columbia MD BLTOMDXIDS0  6050 GLOBAL CROSSING LOCAL SERVICES, INC. - MD 238      
443-393 5 Columbia MD BLTOMDXIDS0  6050 GLOBAL CROSSING LOCAL SERVICES, INC. - MD 238      
443-393 6 Columbia MD BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2006-05-08   
443-393 7 Columbia MD BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2011-04-03   
443-393 8 Columbia MD BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-393 9 Columbia MD BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      

Last updated: Wed, 01 Jun 2022 03:09:23 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.