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.

Waterloo, MD

1 2 >>

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
410-799 A EKRGMDELDS0  9212 VERIZON MARYLAND, INC. 238      
410-904 A BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238      
410-904 0   2593 CORE COMMUNICATIONS, INC.- MD 238   2018-10-23   
410-904 1   2593 CORE COMMUNICATIONS, INC.- MD 238   2018-10-23   
410-904 2 BLTMMDCH08Z  4492 VDL, INC. DBA GLOBAL TELECOM BROKERS - MD 238   2004-02-14   
410-904 3   2593 CORE COMMUNICATIONS, INC.- MD 238   2004-04-02   
410-904 5 BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238   2015-03-18   
410-904 6 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2021-05-21   
410-904 7 BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238      
410-904 8 BLTQMD018MD  145J TERRA NOVA TELECOM INC. 238   2024-02-15   
410-904 9 BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238      
443-284 A BLTMMD91GT0  2593 CORE COMMUNICATIONS, INC.- MD 238      
443-284 2   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-05-02   
443-284 3   2593 CORE COMMUNICATIONS, INC.- MD 238   2018-06-16   
443-284 5   2593 CORE COMMUNICATIONS, INC.- MD 238   2018-06-16   
443-284 6   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-05-02   
443-284 7   2593 CORE COMMUNICATIONS, INC.- MD 238   2018-10-23   
443-296 A   6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-296 0 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2024-12-02   
443-296 2 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2008-12-11   
443-296 3 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2006-01-02   
443-296 5 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2012-10-08   
443-296 6 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2009-07-11   
443-296 7 BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238   2005-03-10   
443-296 8 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2005-08-14   
443-296 9 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2005-08-14   
443-620 A CLMAMDNIDS1  7325 TELEPORT COMMUNICATIONS AMERICA, LLC - MD 238      
443-620 0 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2010-02-22   
443-620 1 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2021-04-29   
443-620 2 BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238   2020-06-05   
443-620 3 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2011-01-09   
443-620 4 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2011-04-04   
443-620 5 BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238   2015-01-05   
443-620 6 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2012-12-01   
443-620 7 BLTMMDDN2MD  508J CENTURYLINK COMMUNICATIONS, LLC 238   2014-04-02   
443-620 8 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2015-03-15   
443-620 9 CLMAMDNIDS1  7325 TELEPORT COMMUNICATIONS AMERICA, LLC - MD 238      
443-661 A   829J PAETEC ITEL, LLC 238   2025-04-01   
443-661 0   829J PAETEC ITEL, LLC 238      
443-661 1   829J PAETEC ITEL, LLC 238      
443-661 2   515J IP HORIZON LLC 238   2017-07-07   
443-661 3   829J PAETEC ITEL, LLC 238      
443-661 4 BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238   2008-10-06   
443-661 5   829J PAETEC ITEL, LLC 238      
443-661 7 BLTMMDCHXVX  321J HD CARRIER LLC 238   2020-05-02   
443-661 8 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2021-04-29   
443-661 9 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2022-09-25   
443-733 A CLMAMDNIDS1  7325 TELEPORT COMMUNICATIONS AMERICA, LLC - MD 238      
443-733 0 BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2003-02-16   
443-733 1   829J PAETEC ITEL, LLC 238   2003-03-04   
443-733 2   829J PAETEC ITEL, LLC 238   2009-03-17   
443-733 3 BLTOMDKHDS0  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 238   2008-10-01   
443-733 4 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2016-04-28   
443-733 5   829J PAETEC ITEL, LLC 238   2013-10-10   
443-733 6 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2016-04-28   
443-733 7   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-05-02   
443-733 8   515J IP HORIZON LLC 238   2016-05-31   
443-733 9 CLMAMDNIDS1  7325 TELEPORT COMMUNICATIONS AMERICA, LLC - MD 238      
443-737 A   829J PAETEC ITEL, LLC 238   2025-04-01   
443-737 0   829J PAETEC ITEL, LLC 238      
443-737 1   829J PAETEC ITEL, LLC 238      
443-737 2 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2005-07-16   
443-737 3   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-05-02   
443-737 4 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2004-02-07   
443-737 5   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-05-02   
443-737 6 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2016-03-21   
443-737 7 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2016-03-21   
443-737 8   515J IP HORIZON LLC 238   2015-03-21   
443-737 9   829J PAETEC ITEL, LLC 238      
443-755 A EKRGMDELDS0  9212 VERIZON MARYLAND, INC. 238      
443-755 0 EKRGMDELDS0  9212 VERIZON MARYLAND, INC. 238      
443-755 1 EKRGMDELDS0  9212 VERIZON MARYLAND, INC. 238      
443-755 2 BLTMMDCHXVX  321J HD CARRIER LLC 238   2016-05-14   
443-755 3 BLTMMDCHYMD  530H WIDE VOICE, LLC - MD 238   2016-05-14   
443-755 4 BLTMMDCHXVX  321J HD CARRIER LLC 238   2016-05-14   
443-755 5 BLTMMDCHXFX  318J COMCAST IP PHONE, LLC 238   2015-08-19   
443-755 6 BLTMMDCHXVX  321J HD CARRIER LLC 238   2016-05-14   
443-755 7 BLTMMDCHXVX  321J HD CARRIER LLC 238   2016-05-14   
443-755 8 EKRGMDELDS0  9212 VERIZON MARYLAND, INC. 238      
443-755 9 EKRGMDELDS0  9212 VERIZON MARYLAND, INC. 238      
443-899 A BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
443-899 0 BLTMMDCHXUX  624H ONVOY SPECTRUM, LLC 238   2021-11-26   
443-899 1 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2021-05-21   
443-899 2 BLTMMDCHXUX  624H ONVOY SPECTRUM, LLC 238   2021-06-26   
443-899 3 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2021-07-12   
443-899 4 BLTMMDCHX7X  073H TELNYX LLC 238   2017-04-26   
443-899 5   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-05-02   
443-899 6   2593 CORE COMMUNICATIONS, INC.- MD 238   2019-05-02   
443-899 7 BLTQMD01DS0  568G PEERLESS NETWORK OF MARYLAND, LLC 238   2013-05-04   
443-899 8 BLTQMD01DS0  568G PEERLESS NETWORK OF MARYLAND, LLC 238   2013-05-04   
443-899 9 BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238      
667-374 A BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238      
667-374 0 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2022-02-05   
667-374 1 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2022-03-11   
667-374 2 BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2022-04-21   
667-374 3   876D ONVOY, LLC - MD 238   2025-02-01   
667-374 5   7325 TELEPORT COMMUNICATIONS AMERICA, LLC - MD 238   2025-02-07   
667-374 6 BLTQMD01BMD  516J TON80 COMMUNICATIONS, LLC 238   2022-03-26   
667-374 7 BLTMMDCH42Z  876D ONVOY, LLC - MD 238   2022-09-25   
667-374 8 BLTMMDCHXUX  624H ONVOY SPECTRUM, LLC 238   2022-02-11   

1 2 >>

Last updated: Sun, 01 Jun 2025 02:18:11 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.