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: MRDLTXXADS0

Remotes:

Switch Switch name Switch type
FNTRTXXARS0  FENTRESS  1RC 
NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
512-357 A Martindale TX 2154 FRONTIER SOUTHWEST INC DBA FRONTIER COMM OF TEXAS 558      

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

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.