Alteration of vehicle

The tax payable under Section 14 in respect of a vehicle which has been altered so as to make it liable to tax at a higher rate than has been paid, will be calculated as follows: "The Taxation Officer will assess in accordance with Sections 4 the amount of tax payable on the vehicle so altered for the period commfencing on the day on which the vehicle was altered and ending with the last day of the period for which tax became first payable on the date of alteration. He will be liable to pay the tax accrued on account of such alteration from the date of such alteration."