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.

Switch: FRDRMDFRXTX

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
240-288 A Thurmont MD 318J COMCAST IP PHONE, LLC 240      
240-943 A Frostburg MD 318J COMCAST IP PHONE, LLC 240      
301-304 A Walkersville MD 318J COMCAST IP PHONE, LLC 240      
301-378 A Frederick MD 318J COMCAST IP PHONE, LLC 240      
301-969 A Brunswick MD 318J COMCAST IP PHONE, LLC 240      
304-378 A Martinsburg WV 318J COMCAST IP PHONE, LLC 240      
681-252 A Charles Town WV 318J COMCAST IP PHONE, LLC 240      
681-446 A Martinsburg WV 318J COMCAST IP PHONE, LLC 240      

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

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