How long do I need have owned my car before selling it at auction? You need to have been the owner of the vehicle for a minimum of 6 months before using this service. Related articles How long does the auction take? Can I change my mind and cancel before the auction ends? Can I advertise my vehicle on Auto Trader and have an auction listing at the same time? Is an MOT required to sell at auction? Can I sell a vehicle via auction for a relative who has passed away?