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 12, MD

<< 1 2 3 4

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
301-679 A WASHDCTTDS0  7529 TELEPORT COMMUNICATIONS AMERICA, LLC - DC 236      
301-679 0 WASHDCDP8MD  071F BANDWIDTH.COM CLEC, LLC - MD 236   2011-05-20   
301-679 1 VINNVACBDS0  876D ONVOY, LLC - MD 236   2008-10-05   
301-679 2 WASKDCFNPS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 236   2008-12-31   
301-679 3 WASHDCDP8MD  071F BANDWIDTH.COM CLEC, LLC - MD 236   2012-04-29   
301-679 4 WASHDCTTDS0  7529 TELEPORT COMMUNICATIONS AMERICA, LLC - DC 236      
301-679 5 WASHDCDP8MD  071F BANDWIDTH.COM CLEC, LLC - MD 236   2012-08-12   
301-679 6 SLSPMD91DS0  568G PEERLESS NETWORK OF MARYLAND, LLC 236   2013-05-03   
301-679 7 VINNVACBDS0  876D ONVOY, LLC - MD 236   2012-10-07   
301-679 8 BTVLMD12CMA  5562 METROPCS, INC. 236   2013-08-14   
301-679 9 BTVLMD12CMA  5562 METROPCS, INC. 236   2013-06-16   
301-847 A BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 0 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 1 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 2 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 3 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 4 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 5 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 6 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 7 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 8 BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-847 9 ARTNVAARXDY  318J COMCAST IP PHONE, LLC 236   2014-10-03   
301-879 A SLSPMDCVDS0  9212 VERIZON MARYLAND, INC. 236      
301-890 A BTVLMDBVDS0  9212 VERIZON MARYLAND, INC. 236      
301-924 A OLNYMDOKRP0  9212 VERIZON MARYLAND, INC. 236      
301-966 A WASHDCINDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 236      
301-966 0 SLSPMD91DS0  568G PEERLESS NETWORK OF MARYLAND, LLC 236   2013-05-03   
301-966 1 FALDMDFLRS0  9212 VERIZON MARYLAND, INC. 236   2012-12-10   
301-966 2 WASHDCDP8MD  071F BANDWIDTH.COM CLEC, LLC - MD 236   2010-08-19   
301-966 3 WASHDCDP8MD  071F BANDWIDTH.COM CLEC, LLC - MD 236   2010-08-19   
301-966 4 FALDMDFLRS0  9212 VERIZON MARYLAND, INC. 236   2012-12-10   
301-966 5 FALDMDFLRS0  9212 VERIZON MARYLAND, INC. 236   2012-12-10   
301-966 6 WASHDCINDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 236      
301-966 7 WASHDCDP8MD  071F BANDWIDTH.COM CLEC, LLC - MD 236   2014-06-06   
301-966 8 FALDMDFLRS0  9212 VERIZON MARYLAND, INC. 236   2012-12-10   
301-966 9 WASHDCINDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 236      
301-989 A SLSPMDCVDS0  9212 VERIZON MARYLAND, INC. 236      

<< 1 2 3 4

Last updated: Thu, 05 Feb 2026 23:41:55 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.