677R21. The carrier shall pay the tax computed on the fair value of each vehicle owned by him in the manner provided for in section 677R13 at the time when the Minister accepts the return provided for in paragraph 2 of section 677R19, except, as the case may be:(1) where he has already paid the tax or, in the case of a supply made under an agreement entered into before 1 July 1992, he has paid the tax provided for in Chapter II of the Retail Sales Tax Act (chapter I-1) in respect of that vehicle; or
(2) where the vehicle in question is a vehicle with which he transported his own merchandise before 1 January 1987.
Subsequently the carrier shall, in the manner provided for in section 677R13, pay the tax computed on the fair value of a motor vehicle assigned to interprovincial transportation where, before being so assigned, it was assigned to intraprovincial or international transportation and for which no tax nor, in the case of a supply made under an agreement entered into before 1 July 1992, the tax provided for in Chapter II of the Retail Sales Tax Act has been paid in Québec.