Guardian and trustee liability extends to payment of GST liabilities incurred by incapacitated persons, recoverable as if they were principals. Where a guardian, trustee or agent conducts a business for a minor or other incapacitated person, tax, interest and penalty in respect of that business shall be levied upon and recoverable from the guardian, trustee or agent in the same manner and to the same extent as if the incapacitated person were a capacitated person conducting the business themselves.