Where do I apply for a USDOT number or inactivate my USDOT? Click here to apply for a USDOT number (or inactivate). September 05, 2015 19:46 Related articles Is a USDOT number required prior to registering for IRP? Where is the Motor Carrier Office located? Do I need an IFTA license? When do my IFTA license and decals expire? What is Intrastate Authority?