If you want to gift a car to a family member, like your spouse, some of the required documents may be different than if you're gifting the car to someone else. For example, an Ontario Safety Standards Certificate isn't required for spouse-to-spouse transfers, but you do have to complete a Spousal Declaration.
Depending on your province, your family member may be exempt from paying retail sales tax (RST) to receive the vehicle – although each province has their own set of rules when it comes to their variation of retail sales tax (RST) and when it should be applied. Some provinces will allow you to give a car to an immediate family member, like a spouse, sibling, child, or grandchild RST-free, but only if it's the first vehicle being gifted within a 12-month period. If, however, you're gifting a car to anyone outside your immediate family, they'll be required to pay RST to complete the ownership transfer.
Check with the Ministry of Transportation in your province to understand which documents you need to complete the transfer of vehicle ownership and whether RST is required.