Can an insurance company put someone on your insurance without your permission?

Answer 1

Technically yes and no. While they can't actually add the driver, they can rate the insurance coverage as if that person would be driving a vehicle. For example, if you had a child who had just gotten their license, and you named them as an excluded driver of your vehicle, yet they somehow managed to get into a small wreck and have to file a claim, your insurance carrier would likely deny the claim on the basis that the driver was excluded, as well as rate your policy as if they were going to be driving the vehicle, without actually adding them.

Moral of the story... don't lie to your insurance company.