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: NRBHMDNEDS0

Remotes:

Switch Switch name Switch type
MUTLMDMTRS0  MUTUAL  5ER 
PRFRMDPFRS1  PRINCE FREDERICK  EXM 
SLMNMDSLRS1  SOLOMONS  EXM 
NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
301-812 A Washington Zone 15 (Baltimore LATA) MD 9212 VERIZON MARYLAND, INC. 238      
301-855 A Washington Zone 15 (Baltimore LATA) MD 9212 VERIZON MARYLAND, INC. 238      
410-257 A North Beach MD 9212 VERIZON MARYLAND, INC. 238      
410-286 A North Beach MD 9212 VERIZON MARYLAND, INC. 238      

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

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