Mr-H - Are you saying that your b-I-l is the policyholder? You certainly don't have to be a driver to be a policyholder. If your b-i-l is the owner, he'll have an insurable interest in the vehicle and, for example, will expect to be paid out if the vehicle is stolen, even if he's not allowed to drive it. (Think of situations where drivers (as policyholders) have a temporary ban on driving.). As Woofgang says, however, the best thing is to talk to the insurer. You'll also have to decide who is the actual 'keeper' of the vehicle, to satisfy DVLA.