Guardian liability: guardians and trustees are liable for GST, interest and penalties as if the minor were capable. Where business subject to tax, interest or penalty is carried on by a guardian, trustee or agent for a minor or other incapacitated person, the guardian, trustee or agent shall be liable for the tax, interest and penalty and such amounts shall be levied and recovered from them in the same manner and to the same extent as if the minor or incapacitated person were a major or capacitated person conducting the business, with all provisions of the Act and rules applying accordingly.