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.

OCN: 958H TRIANGLE COMMUNICATION SYSTEM, INC. - MT-

NPA-NXX BLOCK Rate Centre Region Switch LATA LIR Eff date Disc date
406-399 8 South Havre MT HAVRMTXCDS1  648      
406-400 A Havre MT HAVRMTXCDS1  648      
406-400 2 Havre MT HAVRMTXCDS1  648      

Last updated: Wed, 20 Nov 2024 21:20:06 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.