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 When do my IFTA license and decals expire? Is a USDOT number required prior to registering for IRP? Do I need an IFTA license? How do I qualify for an exemption of sales tax on industrial machinery purchased to fabricate the product I manufacture? I have questions about IFTA and filing my return. Who should I contact?