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: 3310 TRIANGLE TEL. COOP. ASSN., INC.

NPA-NXX BLOCK Rate Centre Region Switch LATA LIR Eff date Disc date
406-353 A Harlem MT FTBNMTXCDS0  648      
406-353 0 Harlem MT FTBNMTXCDS0  648      
406-353 2 Harlem MT FTBNMTXCDS0  648      
406-353 3 Harlem MT FTBNMTXCDS0  648      
406-353 4 Harlem MT FTBNMTXCDS0  648      
406-353 7 Harlem MT FTBNMTXCDS0  648      
406-353 8 Harlem MT FTBNMTXCDS0  648      
406-374 A Moore MT FTBNMTXCDS0  648      
406-383 A Dodson MT FTBNMTXCDS0  648      
406-423 A Hobson MT FTBNMTXCDS0  648      
406-473 A Judith Gap MT FTBNMTXCDS0  648      
406-547 A White Sulphur Springs MT WSSPMTXCDS0  650      
406-547 0 White Sulphur Springs MT WSSPMTXCDS0  650      
406-547 2 White Sulphur Springs MT WSSPMTXCDS0  650      
406-547 3 White Sulphur Springs MT WSSPMTXCDS0  650      
406-547 6 White Sulphur Springs MT WSSPMTXCDS0  650      
406-566 A Stanford MT FTBNMTXCDS0  648      
406-566 1 Stanford MT   648      
406-566 2 Stanford MT   648      
406-566 3 Stanford MT   648      
406-566 4 Stanford MT   648      
406-566 5 Stanford MT   648      
406-566 8 Stanford MT   648      
406-566 9 Stanford MT   648      
406-567 A Denton MT FTBNMTXCDS0  648      
406-572 A Martinsdale MT WSSPMTXCDS0  650      
406-622 A Fort Benton MT FTBNMTXCDS0  648      
406-622 0 Fort Benton MT FTBNMTXCDS0  648      
406-622 2 Fort Benton MT FTBNMTXCDS0  648      
406-622 3 Fort Benton MT FTBNMTXCDS0  648      
406-622 4 Fort Benton MT FTBNMTXCDS0  648      
406-622 5 Fort Benton MT FTBNMTXCDS0  648      
406-622 6 Fort Benton MT FTBNMTXCDS0  648      
406-632 A Harlowton MT WSSPMTXCDS0  650      
406-632 1 Harlowton MT WSSPMTXCDS0  650      
406-632 2 Harlowton MT WSSPMTXCDS0  650      
406-632 3 Harlowton MT WSSPMTXCDS0  650      
406-632 4 Harlowton MT WSSPMTXCDS0  650      
406-632 5 Harlowton MT WSSPMTXCDS0  650      
406-632 6 Harlowton MT WSSPMTXCDS0  650      
406-632 7 Harlowton MT WSSPMTXCDS0  650      
406-632 9 Harlowton MT WSSPMTXCDS0  650      
406-654 A Malta MT MALTMTXCDS0  648      
406-654 0 Malta MT MALTMTXCDS0  648      
406-654 1 Malta MT MALTMTXCDS0  648      
406-654 2 Malta MT MALTMTXCDS0  648      
406-654 5 Malta MT MALTMTXCDS0  648      
406-654 7 Malta MT MALTMTXCDS0  648      
406-737 A Geraldine MT FTBNMTXCDS0  648      

Last updated: Sun, 17 May 2026 03:26:51 UTC

Sponsored by: LES.NET

Like this site? We accept donations via PayPal.