74. A registrant who receives a zero-rated supply of a continuous transmission commodity that is not subsequently exported or supplied, as required for zero-rating under section 15.2 of Part V of Schedule VI, is required to add an amount to its net tax for the reporting period that includes the earliest day in which tax on the initial supply would have become payable had that supply not been a zero rated supply. This net tax adjustment reflects the cash flow benefit obtained by the registrant in having received a supply on a zero-rated basis.
75. The amount to be added to net tax is equal to interest, at the prescribed rate, calculated on the total amount of tax that would have been payable in respect of the supply.