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.
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Switch: DLFTMNXDRS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
507-678 A Delft MN 1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 620      
507-678 0 Delft MN 1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 620      
507-678 1 Delft MN 1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 620      
507-678 2 Delft MN 1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 620      
507-678 6 Delft MN 1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 620      
507-678 7 Delft MN 1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 620      
507-678 8 Delft MN 1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 620      
507-678 9 Delft MN 1123 CITIZENS TELECOM CO MN-FRONTIER CITIZENS COM-MN 620      

Last updated: Sat, 21 Mar 2026 23:53:39 UTC

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