We just did this last month with a casita
which we brought to ontario from Michigan.
1. Have bill of sale. This determines the taxes.😊
2. Have title
signed by the owner.
3. We did not need plates for Michigan. We had 3 days to drive it home. We DID make sure we had insured it by calling our car insurance provider.
4. At the border we supplied the title
and bill of sale. We then paid the federal portion of the hst (5%?).
5. We then went to the nearest license
office (sarnia) and got a plate. We then paid the provincial portion of the hst (8%).
6. A few weeks later we get a notice from RIV in the mail telling us to go on line, fill in a form with info off the manufacturer's plate, and pay $335. A week or so later we get a form from RIV to take to an approved inspector. There is a link to find the nearest one. Hmmm, they were all Canadian Tire stores
7. We go to Can Tire and get "inspected". The inspector faxes the form to RIV. A couple weeks later we get a sticker to affix to the trailer next to the USA one.
8. As a special added task, we got a notice from the ontario license
office that the title
was wrong because the clerk forgot to convert pounds to kilograms so they needed to re-issue it.
We did not have to drive over provincial borders to get it home so I speak to how long you can drive it around without plates.