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: GRRNMTXCRS1

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
406-428 A Grass Range MT 2246 MID-RIVERS TELEPHONE COOPERATIVE, INC. 650      

Last updated: Mon, 24 May 2021 01:28:43 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.