Obligation on revision of rate of tax

If as a result of revision of rate of tax levied under this Act, a motor vehicle in respect of which tax has been paid for a particular period becomes liable to tax at higher rate at any time during such period, the owner of the motor vehicle, shall be liable to pay additional tax equal to the difference between the tax already paid and the tax which becomes payable at higher rate due to such revision, within the time specified in the notification issued under section 3, for the remainder of such period.