https://www.legalline.ca/legal-answers/buying-a-used-vehicle/#:~:text=If%20you%20purchased%20the%20used,(RST)%20of%2013%25.
Once you buy a used vehicle, you are required by law to take the Package to a ServiceOntario centre to register as the new owner and pay sales tax within six days of the sale. If you purchased the used vehicle from a car dealer, you will be required to pay the provincial-federal Harmonized Sales Tax (HST). If your vehicle was purchased privately, you will not pay the Harmonized Sales Tax (HST),
but the Ontario government will still charge you a provincial retail sales tax (RST) of 13%. The government believes this heightened tax rate helps maintain a “level playing field” for used car dealers, who must charge the HST. Regardless, either tax will be based on either the purchase price of the vehicle, or the average wholesale value of the vehicle listed in the UVIP, whichever is greater.