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 4, MD

<< 1 2 3 4 5 6 7 8 9 10 11 12 >>

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
301-484 A ARTNVAARXDY  318J COMCAST IP PHONE, LLC 236      
301-531 A LNHMMDADGT0  8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
301-531 0 BTVLMD12CMA  6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 236   2012-03-25   
301-531 1 LNHMMDADGT0  8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
301-531 2 LNHMMDADGT0  8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
301-531 3 LNHMMDADGT0  8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
301-531 4 WASHDCDP8MD  071F BANDWIDTH.COM CLEC, LLC - MD 236   2010-02-22   
301-531 5 WASHDCDP8MD  071F BANDWIDTH.COM CLEC, LLC - MD 236   2010-02-22   
301-531 6 LNHMMDADGT0  8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
301-531 7 LNHMMDADGT0  8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
301-531 8 LNHMMDADGT0  8832 STARPOWER COMMUNICATIONS, LLC - MD 236      
301-531 9 HRNDVACKAMD  1958 ATX TELECOMMUNICATIONS SERVICES, LTD. 236   2003-04-06   
301-546 A LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-546 0   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 1   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 2   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 3   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 4   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 5   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 6   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 7   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 8   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-546 9   9212 VERIZON MARYLAND, INC. 236   2014-06-06   
301-559 A HYVLMDCMDS0  9212 VERIZON MARYLAND, INC. 236      
301-560 A CHCHMDBE6MD  4716 PAETEC COMMUNICATIONS, INC. - MD 236      
301-577 A LNHMMDLNDS0  9212 VERIZON MARYLAND, INC. 236      
301-583 A LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 0 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 1 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 2 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 3 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 4 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 5 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 6 BTVLMD127MD  5562 METROPCS, INC. 236   2013-06-03   
301-583 7 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 8 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-583 9 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-618 A LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-618 0 SLSPMD91DS0  568G PEERLESS NETWORK OF MARYLAND, LLC 236   2013-05-03   
301-618 1 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-618 2 TYCRVA03AMD  2589 US LEC OF MARYLAND, INC. 236      
301-618 3 TYCRVA03AMD  2589 US LEC OF MARYLAND, INC. 236      
301-618 4 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-618 5 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-618 6 TYCRVA03AMD  2589 US LEC OF MARYLAND, INC. 236      
301-618 7 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-618 8 LDVRMDLODS0  9212 VERIZON MARYLAND, INC. 236      
301-618 9 WASLDCRGDS0  281E YMAX COMMUNICATIONS CORP. - MD 236   2008-10-10   
301-683 A WASHDCTTDS0  7529 TELEPORT COMMUNICATIONS AMERICA, LLC - DC 236      
301-683 0 WASHDCTTDS0  7529 TELEPORT COMMUNICATIONS AMERICA, LLC - DC 236      

<< 1 2 3 4 5 6 7 8 9 10 11 12 >>

Last updated: Tue, 16 Apr 2024 01:38:01 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.