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.

St Mary, MT

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
406-732 A STMYMTMARS1  9636 QWEST CORPORATION 648      
406-732 0   073H TELNYX LLC 648   2020-08-13   
406-732 1   624H ONVOY SPECTRUM, LLC 648   2020-11-08   
406-732 2   453F ONVOY, LLC - MT 648   2019-09-15   
406-732 3   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 648   2014-05-24   
406-732 4   9636 QWEST CORPORATION 648      
406-732 5   9636 QWEST CORPORATION 648      
406-732 6   453F ONVOY, LLC - MT 648   2007-03-19   
406-732 7   453F ONVOY, LLC - MT 648   2019-09-15   
406-732 8   453F ONVOY, LLC - MT 648   2011-10-24   
406-732 9   9636 QWEST CORPORATION 648      

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

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.