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.

West Oslo, ND

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
701-699 A OSLOMNXORS0  1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 636      
701-699 0   452F ONVOY, LLC - ND 636   2020-12-11   
701-699 1   1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 636      
701-699 2   1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 636      
701-699 3   1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 636      
701-699 4   452F ONVOY, LLC - ND 636   2020-08-20   
701-699 5   1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 636      
701-699 6   452F ONVOY, LLC - ND 636   2020-04-01   
701-699 7   508J CENTURYLINK COMMUNICATIONS, LLC 636   2017-06-05   
701-699 8   8054 LEVEL 3 COMMUNICATIONS, LLC - ND 636   2023-03-19   
701-699 9   1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 636      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.