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: 392

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-392 A Baltimore MD BLTMMDFMDS0  7325 TELEPORT COMMUNICATIONS AMERICA, LLC - MD 238      
443-392 0 Baltimore MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2003-10-11   
443-392 1 Baltimore MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2003-10-11   
443-392 2 Baltimore MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2003-10-11   
443-392 3 Baltimore MD   876D ONVOY, LLC - MD 238   2024-02-24   
443-392 4 Baltimore MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2003-10-11   
443-392 5 Baltimore MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2003-10-11   
443-392 6 Baltimore MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2003-10-11   
443-392 7 Baltimore MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2004-06-10   
443-392 8 Baltimore MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2004-06-18   
443-392 9 Baltimore MD   7325 TELEPORT COMMUNICATIONS AMERICA, LLC - MD 238      

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.