It is not possible to change the main policyholder once you have bought a policy with Marshmallow.
This is because we work out insurance individually for each policyholder. Whether we can offer a price depends on many different factors such as your driving history, credit history, and information about your car - even its age and engine size.
However, as a solution, you can cancel your policy and purchase a new one in the correct name, as the insurance would be calculated given the person's details.
Main Driver
The policyholder tends to be the main driver on the policy and needs to be an 'insurable interest.'
If your spouse is not the policyholder but uses the vehicle more and owns it, then this is fine as long as you both live at the same address. In this case, you don't need to cancel just because you would like your spouse to be the main driver on the policy.