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 13, MD

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

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
301-426 6 WASKDCFNPS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 236      
301-426 7 MRKKMDMKDS0  9212 VERIZON MARYLAND, INC. 236      
301-426 8 MRKKMDMKDS0  9212 VERIZON MARYLAND, INC. 236      
301-426 9 MRKKMDMKDS0  9212 VERIZON MARYLAND, INC. 236      
301-441 A CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 A CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 0 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 1 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 2 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 3 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 4 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 5   2593 CORE COMMUNICATIONS, INC.- MD 236   2019-04-29   
301-446 6 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 7 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 8 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-446 9 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-474 A CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-477 A ARTNVAARXDY  318J COMCAST IP PHONE, LLC 236      
301-477 1 ARTNVAARXDY  318J COMCAST IP PHONE, LLC 236      
301-477 2 ARTNVAARXDY  318J COMCAST IP PHONE, LLC 236      
301-477 3 ARTNVAARXDY  318J COMCAST IP PHONE, LLC 236      
301-477 4 ARTNVAARXDY  318J COMCAST IP PHONE, LLC 236   2017-02-01   
301-477 5   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-477 6   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-477 7 ARTNVAARXDY  318J COMCAST IP PHONE, LLC 236   2015-09-04   
301-477 8 VINNVACBDS0  876D ONVOY, LLC - MD 236   2018-01-14   
301-477 9 VINNVACBDS0  876D ONVOY, LLC - MD 236   2018-01-14   
301-479 A WASKDCFNPS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 236      
301-479 1 WASKDCFNPS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 236      
301-479 2   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-479 3 WASKDCFNPS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 236      
301-479 4   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-479 5 VINNVACBDS0  876D ONVOY, LLC - MD 236   2023-06-17   
301-479 6 VINNVACBDS0  876D ONVOY, LLC - MD 236   2023-06-17   
301-479 7   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-479 8 VINNVACBDS0  876D ONVOY, LLC - MD 236   2023-06-17   
301-479 9 VINNVACBDS0  876D ONVOY, LLC - MD 236   2023-06-17   
301-486 A CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-486 0 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-486 1 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-486 2 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-486 3 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-486 4 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-486 5   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-486 6 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-486 7 CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-486 8   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-486 9   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-488 A CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      
301-489 A CLPKMDBWDS0  9212 VERIZON MARYLAND, INC. 236      

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

Last updated: Fri, 22 Mar 2024 03:02:44 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.