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.

Washington Zone 16, MD

1 2 3 4 5 >>

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
227-222 A WASHDCSWFMD  530H WIDE VOICE, LLC - MD 236      
227-222 0   876D ONVOY, LLC - MD 236   2024-06-08   
227-222 1   071F BANDWIDTH.COM CLEC, LLC - MD 236   2024-11-11   
227-222 2   530H WIDE VOICE, LLC - MD 236   2023-12-18   
227-222 3   624H ONVOY SPECTRUM, LLC 236   2024-01-14   
227-222 4   624H ONVOY SPECTRUM, LLC 236   2024-01-14   
227-222 5   876D ONVOY, LLC - MD 236   2025-05-10   
227-222 6   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2025-07-27   
227-222 7   321J HD CARRIER LLC 236   2023-12-18   
227-222 8   876D ONVOY, LLC - MD 236   2025-03-09   
227-222 9   876D ONVOY, LLC - MD 236   2024-11-10   
227-333 A   876D ONVOY, LLC - MD 236   2025-10-16   
227-333 0   876D ONVOY, LLC - MD 236   2025-10-17   
227-333 3   876D ONVOY, LLC - MD 236   2025-10-16   
227-333 4   876D ONVOY, LLC - MD 236   2025-10-16   
227-333 5   876D ONVOY, LLC - MD 236   2025-10-16   
227-333 6   876D ONVOY, LLC - MD 236   2025-10-16   
240-244 A LNHMMDADGT0  8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
240-244 0   071F BANDWIDTH.COM CLEC, LLC - MD 236   2010-09-03   
240-244 1   318J COMCAST IP PHONE, LLC 236   2006-03-03   
240-244 2   318J COMCAST IP PHONE, LLC 236   2016-06-07   
240-244 3   071F BANDWIDTH.COM CLEC, LLC - MD 236   2007-09-13   
240-244 4   876D ONVOY, LLC - MD 236   2008-10-05   
240-244 5   318J COMCAST IP PHONE, LLC 236   2007-01-19   
240-244 6   071F BANDWIDTH.COM CLEC, LLC - MD 236   2010-02-22   
240-244 7   071F BANDWIDTH.COM CLEC, LLC - MD 236   2010-10-28   
240-244 8   8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
240-244 9   071F BANDWIDTH.COM CLEC, LLC - MD 236   2008-12-13   
240-269 A SLSPMD91DS0  568G PEERLESS NETWORK OF MARYLAND, LLC 236      
240-269 0   145J TERRA NOVA TELECOM INC. 236   2023-08-06   
240-269 1   568G PEERLESS NETWORK OF MARYLAND, LLC 236   2021-12-30   
240-269 2   876D ONVOY, LLC - MD 236   2021-09-24   
240-269 3   876D ONVOY, LLC - MD 236   2021-09-24   
240-269 4   876D ONVOY, LLC - MD 236   2021-09-24   
240-269 5   876D ONVOY, LLC - MD 236   2021-12-23   
240-269 6   876D ONVOY, LLC - MD 236   2021-12-23   
240-269 7   876D ONVOY, LLC - MD 236   2021-12-23   
240-269 8   624H ONVOY SPECTRUM, LLC 236   2022-01-28   
240-269 9   568G PEERLESS NETWORK OF MARYLAND, LLC 236      
240-303 A   829J PAETEC ITEL, LLC 236   2025-04-02   
240-303 0   829J PAETEC ITEL, LLC 236      
240-303 1   829J PAETEC ITEL, LLC 236      
240-303 2   071F BANDWIDTH.COM CLEC, LLC - MD 236   2011-02-26   
240-303 3   876D ONVOY, LLC - MD 236   2012-10-07   
240-303 4   829J PAETEC ITEL, LLC 236      
240-303 5   876D ONVOY, LLC - MD 236   2020-06-11   
240-303 6   876D ONVOY, LLC - MD 236   2020-06-11   
240-303 7   876D ONVOY, LLC - MD 236   2020-06-11   
240-303 8   876D ONVOY, LLC - MD 236   2020-06-11   
240-303 9   829J PAETEC ITEL, LLC 236      

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.