To haul across state lines, you need Interstate Operating Authority - a "Motor Carrier (MC) Number" from FMCSA. Get your own trucking authority in Texas with our comprehensive trucking authority packages and expert services.Complete Trucking Authority Packages. Our complete authority packages are designed to give you every filing actually required to get you on the road. You can use a credit or debit card. FMCSA operating authority is often identified as an "MC," "FF," or "MX" number, depending on the type of authority that is granted. Forming an LLC for a trucking company requires more than just filing documents with your secretary of state. Here's what's required. When we partner with intrastate trucking companies, we will research the laws in your state and find out if authority letters are required. Important 2024 update: The MC number is on its way out.