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.

Catonsville, MD

<< 1 2 3 4 5 >>

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
410-869 1   9212 VERIZON MARYLAND, INC. 238      
410-869 2   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-04-05   
410-869 3   9212 VERIZON MARYLAND, INC. 238      
410-869 4   9212 VERIZON MARYLAND, INC. 238      
410-869 5   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2021-12-09   
410-869 6   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-04-05   
410-869 7   9212 VERIZON MARYLAND, INC. 238      
410-869 8   9212 VERIZON MARYLAND, INC. 238      
410-869 9   9212 VERIZON MARYLAND, INC. 238      
410-917 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
410-926 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
410-926 0   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
410-926 1   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-14   
410-926 2   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-14   
410-926 3   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2024-04-22   
410-926 4   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-926 5   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-926 6   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-926 7   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-926 8   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-926 9   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
410-948 0   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
410-948 1   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 2   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 3   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 4   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 5   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 6   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 7   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 8   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-948 9   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-11   
410-971 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
410-978 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
410-979 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
443-251 A BLTMMDCH42Z  876D ONVOY, LLC - MD 238      
443-251 0   876D ONVOY, LLC - MD 238   2014-09-05   
443-251 1   515J IP HORIZON LLC 238   2013-10-11   
443-251 2   318J COMCAST IP PHONE, LLC 238   2014-02-12   
443-251 3   876D ONVOY, LLC - MD 238   2014-12-31   
443-251 4   876D ONVOY, LLC - MD 238   2014-12-31   
443-251 5   318J COMCAST IP PHONE, LLC 238   2014-08-21   
443-251 6   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2014-12-13   
443-251 7   508J CENTURYLINK COMMUNICATIONS, LLC 238   2014-04-02   
443-251 8   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2014-10-10   
443-251 9   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2013-12-09   
443-315 A   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
443-315 0   145J TERRA NOVA TELECOM INC. 238   2025-05-28   
443-315 2   876D ONVOY, LLC - MD 238   2013-08-01   
443-315 3   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-315 5   318J COMCAST IP PHONE, LLC 238   2012-05-26   
443-315 6   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-315 7   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-315 8   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-315 9   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-341 A BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-341 0   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-341 1   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-341 2   4492 VDL, INC. DBA GLOBAL TELECOM BROKERS - MD 238   2004-02-14   
443-341 3   2593 CORE COMMUNICATIONS, INC.- MD 238   2004-03-29   
443-341 4   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2003-02-20   
443-341 5   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2004-12-27   
443-341 6   318J COMCAST IP PHONE, LLC 238   2005-03-10   
443-341 7   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-19   
443-341 8   829J PAETEC ITEL, LLC 238   2004-03-27   
443-341 9   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-474 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
443-498 A BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-498 0   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-498 1   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-498 2   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-498 3   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-19   
443-498 4   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-498 5   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-498 6   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-04-30   
443-498 7   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-04-30   
443-498 8   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-19   
443-498 9   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238      
443-514 A   829J PAETEC ITEL, LLC 238   2025-04-01   
443-514 0   829J PAETEC ITEL, LLC 238      
443-514 1   829J PAETEC ITEL, LLC 238      
443-514 2   829J PAETEC ITEL, LLC 238      
443-514 3   7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238   2021-05-13   
443-514 4   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-514 5   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-514 6   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-514 7   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-02-05   
443-514 8   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-03-19   
443-514 9   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2021-06-06   
443-520 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
443-612 A CTVLMDCTDS0  9212 VERIZON MARYLAND, INC. 238      
443-631 A CLMAMDORGT0  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238      
443-631 0   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-10-07   
443-631 1   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-10-07   
443-631 2   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-10-10   
443-631 3   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-10-07   
443-631 4   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-10-07   
443-631 5   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-10-07   
443-631 6   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-10-07   
443-631 7   4036 NEW CINGULAR WIRELESS PCS, LLC - DC 238   2005-10-07   

<< 1 2 3 4 5 >>

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.