If your driving for an operator, just as the operator (owner) does, you should know where every dime goes from the unit you operate. My drivers have an agreement with me on their pay. They get a copy of all paperwork generated from every load they carry or responsible for. They also have a contract with me on their pay. I pay them when they turn in the paper work whether or not I'm am paid yet.
It's a business whether you own the vehicle or just drive it, it's your lively hood. Even if your new to this game or not, keep a copy of everything you do. File it physically and mentally, it will save you in the long run.