When you buy a trailer from someone else in Ontario, you will be required to transfer ownership of the vehicle and register it with the Ontario Ministry of Transportation. You will need to provide the appropriate documentation as well as pay the required fees for licensing and new plates if required. Transferring ownership of a trailer is similar to the process for a used car, but there is less documentation required and the fees are generally lower.
Obtain a bill of sale from the previous owner of the trailer stating the date of sale and the amount of the purchase price. It should also list the year, make and model of the trailer as well as the vehicle identification number. Ensure that the previous owner signs this document. You can write up a simple bill of sale yourself, or use a free online template like the one you can find at the Business Form Template website.