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.

NPA: 406 [Rate centres in NPA 406] [Dial plan for NPA 406]

NXX: 328

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-328 A Absarokee MT ABSRMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-328 3 Absarokee MT BLNGMTWE6MD  9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650   2023-03-29   
406-328 4 Absarokee MT ABSRMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-328 6 Absarokee MT ABSRMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-328 7 Absarokee MT ABSRMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-328 8 Absarokee MT ABSRMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-328 9 Absarokee MT ABSRMTXCDS0  2250 PROJECT TEL. CO., INC. 650      

Last updated: Sat, 05 Apr 2025 03:03:23 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.