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.

Columbia, MD

<< 1 2 3 4 5 >>

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
443-319 5 BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238   2005-03-10   
443-319 6   829J PAETEC ITEL, LLC 238      
443-319 7 BLTMMDCH40Z  5562 METROPCS, INC. 238   2016-02-03   
443-319 8 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2010-11-19   
443-319 9   829J PAETEC ITEL, LLC 238      
443-367 A CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238      
443-367 0 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238      
443-367 1 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2005-07-02   
443-367 2 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238      
443-367 3 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238      
443-367 4   829J PAETEC ITEL, LLC 238   2007-06-15   
443-367 5 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238      
443-367 6   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-03-28   
443-367 7 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238      
443-367 8 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2011-10-28   
443-367 9 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2011-04-03   
443-393 A   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-393 0 CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2025-01-08   
443-393 1 CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2025-01-08   
443-393 2 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2005-09-10   
443-393 3 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2005-09-10   
443-393 4   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-393 5   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-393 6 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2006-05-08   
443-393 7 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2011-04-03   
443-393 8 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-393 9 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-430 A BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-430 0 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-430 1   515J IP HORIZON LLC 238   2016-10-14   
443-430 2 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2005-08-14   
443-430 3 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-430 4 CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2016-09-26   
443-430 5 CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2016-09-26   
443-430 6 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2005-08-14   
443-430 7 BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238   2008-05-30   
443-430 8 BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238   2006-03-11   
443-430 9 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-472 A BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-472 0 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2004-06-03   
443-472 1 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2003-11-19   
443-472 2 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2003-11-03   
443-472 3 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2004-08-02   
443-472 4 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-472 5 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2004-11-04   
443-472 6 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2005-01-02   
443-472 7 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2004-02-28   
443-472 8 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2005-01-02   
443-472 9 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2005-11-01   
443-518 A CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238      
443-518 0 CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2009-05-26   
443-518 1 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 2 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 3 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 4 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 5 CLMAMDCBRP0  9212 VERIZON MARYLAND, INC. 238   2009-03-02   
443-518 6 CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2009-05-26   
443-518 7 WASKDCFNPS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2010-04-08   
443-518 8 CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2010-03-29   
443-518 9 CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2009-06-23   
443-535 A CLVLMDCERP0  9212 VERIZON MARYLAND, INC. 238   2024-01-30   
443-535 0 CLVLMDCERP0  9212 VERIZON MARYLAND, INC. 238      
443-535 1 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2011-05-20   
443-535 2 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2005-09-15   
443-535 3 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2006-01-21   
443-535 4 BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238   2006-05-15   
443-535 5 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2007-02-08   
443-535 6 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2011-03-21   
443-535 7 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2009-07-09   
443-535 8 CLVLMDCERP0  9212 VERIZON MARYLAND, INC. 238      
443-535 9 CLVLMDCERP0  9212 VERIZON MARYLAND, INC. 238      
443-537 A BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238      
443-537 0 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2009-10-30   
443-537 1 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2009-10-25   
443-537 2   829J PAETEC ITEL, LLC 238   2011-03-11   
443-537 3 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2010-06-03   
443-537 4 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2009-07-13   
443-537 5 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2010-06-14   
443-537 6 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2010-06-14   
443-537 7 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2010-06-14   
443-537 8 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2010-06-14   
443-537 9 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2011-02-05   
443-538 A BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238      
443-539 A   829J PAETEC ITEL, LLC 238   2025-04-01   
443-539 0   829J PAETEC ITEL, LLC 238      
443-539 1   829J PAETEC ITEL, LLC 238      
443-539 2   829J PAETEC ITEL, LLC 238      
443-539 3   829J PAETEC ITEL, LLC 238      
443-539 4   829J PAETEC ITEL, LLC 238   2006-08-15   
443-539 5 BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238   2008-10-01   
443-539 6 BLTOMDKHBMD  6395 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 238   2011-10-28   
443-539 7 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2010-02-15   
443-539 8 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2008-02-13   
443-539 9   829J PAETEC ITEL, LLC 238      
443-542 A BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238      
443-542 0 BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238      
443-542 1 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2004-11-25   
443-542 2 BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238      
443-542 3 BLTMMDCH40Z  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2005-03-12   
443-542 4 CLMAMDSRRS0  9212 VERIZON MARYLAND, INC. 238   2004-12-20   

<< 1 2 3 4 5 >>

Last updated: Thu, 16 Oct 2025 03:04:18 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.