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.

Denton, MD

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
410-479 A DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
410-479 0 DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
410-479 1 DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
410-479 2 DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
410-479 3 DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
410-479 4 DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
410-479 5 DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
410-479 6   2593 CORE COMMUNICATIONS, INC.- MD 242   2004-04-03   
410-479 7   829J PAETEC ITEL, LLC 242   2010-06-27   
410-479 8 DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
410-479 9 DNTNMDDTRS0  9212 VERIZON MARYLAND, INC. 242      
443-448 A SLBRMDSBXLX  318J COMCAST IP PHONE, LLC 242      
443-448 1 SLBRMDSBXVX  876D ONVOY, LLC - MD 242   2021-03-05   
443-448 2 SLBRMDSBX0X  624H ONVOY SPECTRUM, LLC 242   2021-12-09   
443-448 3 ESTNMDES5MD  7228 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 242   2015-11-02   
443-448 4 SLBRMDSBXLX  318J COMCAST IP PHONE, LLC 242   2006-07-31   
443-448 5 SLBRMDSBXFX  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 242   2016-10-16   
443-448 6 SLBRMDSBXUX  7325 TELEPORT COMMUNICATIONS AMERICA, LLC - MD 242   2014-06-25   
443-448 7 SLBRMDSBXLX  318J COMCAST IP PHONE, LLC 242   2015-03-20   
443-448 8 SLBRMDSBXVX  876D ONVOY, LLC - MD 242   2017-04-13   
443-448 9 SLBRMD902MD  073H TELNYX LLC 242   2017-09-13   
667-248 A ESTNMDBNGT0  2593 CORE COMMUNICATIONS, INC.- MD 242      
667-248 0   2593 CORE COMMUNICATIONS, INC.- MD 242   2018-08-03   
667-248 1   2593 CORE COMMUNICATIONS, INC.- MD 242   2018-08-03   
667-248 2   2593 CORE COMMUNICATIONS, INC.- MD 242   2018-08-03   
667-248 3 ESTNMDBNGT0  2593 CORE COMMUNICATIONS, INC.- MD 242   2019-03-28   
667-248 4 ESTNMDBNGT0  2593 CORE COMMUNICATIONS, INC.- MD 242   2019-03-28   
667-248 5 SLBRMD90DS0  2593 CORE COMMUNICATIONS, INC.- MD 242   2019-07-31   
667-248 6 ESTNMDBNGT0  2593 CORE COMMUNICATIONS, INC.- MD 242   2019-03-28   
667-248 7 ESTNMDBNGT0  2593 CORE COMMUNICATIONS, INC.- MD 242   2019-03-28   
667-248 8 SLBRMDSBXVX  876D ONVOY, LLC - MD 242   2019-03-04   
667-248 9 SLBRMDSBXVX  876D ONVOY, LLC - MD 242   2019-03-04   
667-467 A SLBRMDSBX0X  624H ONVOY SPECTRUM, LLC 242      
667-467 0 SLBRMD901MD  939H COMMIO, LLC 242   2022-11-07   
667-467 2 SLBRMDSBXVX  876D ONVOY, LLC - MD 242   2022-10-16   
667-467 3 SLBRMD90BMD  516J TON80 COMMUNICATIONS, LLC 242   2022-03-21   
667-467 4 SLBRMDSBX0X  624H ONVOY SPECTRUM, LLC 242   2021-08-16   
667-467 5 SLBRMDSBXVX  876D ONVOY, LLC - MD 242   2021-09-25   
667-467 6 SLBRMDSBX0X  624H ONVOY SPECTRUM, LLC 242   2021-11-15   
667-467 7 SLBRMDSBXVX  876D ONVOY, LLC - MD 242   2021-12-20   

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.