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: STLDMDSLDS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
240-721 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-420 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-516 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-568 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-669 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-735 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-736 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-763 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-817 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      
301-967 A Washington Zone 5 MD 9212 VERIZON MARYLAND, INC. 236      

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.