Exactly. They should be logging their KM for each trip as an Uber driver, since they are not taxi's and only go around when given a call. This is an issue as I am sure most Uber drivers don't report properly. Log books would be most effective, as it is similar to a company giving you a vehicle for personal use. In that case, you have to track all personal mileage used. In Uber driver cases, you do the reverse. Track all business mileage on the vehicle. They should have records of all maintenance done on the vehicle for the year, and all fuel expenses. For fuel expenses, the easiest way is for them to use a single Credit Card, or debit card, for only car related expenses. Easier to total at the end, but receipts are still required.