Sch 9ZE para 27
(1) This paragraph applies where— (a) a person makes a special scheme return for a tax period (“ the affected tax period ”) relating (wholly or partly) to a UK supply, and (b) after the return has been made the amount of the consideration for the UK supply increases or decreases. (2) The person must, in the tax period in which the increase or decrease is accounted for in the person's business accounts— (a) amend the special scheme return to take account of the increase or decrease, or (b) (if the period during which the person is entitled under Article 61 of the Implementing Regulation to amend the special scheme return has expired) notify the Commissioners of the adjustment needed to the figures in the special scheme return because of the increase or decrease. (3) Where the change to which an amendment or notice under sub-paragraph (2) relates is an increase in the consideration for a UK supply, the person must pay to the tax authorities for the administering member State (in accordance with Article 62 of the Implementing Regulation) or, in a case falling within sub-paragraph (2)(b), the Commissioners, the difference between— (a) the amount of VAT that was chargeable on the supply before the increase in consideration, and (b) the amount of VAT that is chargeable in respect of the whole of the increased consideration for the supply. (4) Where the change to which an amendment or notice under sub-paragraph (2) relates is a decrease in the consideration for a UK supply, the amendment or notice has effect as a claim; and where a claim is made the Commissioners must repay any VAT paid by the person that would not have been VAT due from the person had the consideration for the supply always been the decreased amount. (5) The Commissioners may by regulations specify— (a) the latest time by which, and the form and manner in which, a claim or other notice under sub-paragraph (2)(b) must be given; (b) the latest time by which, and the form in which, a payment under sub-paragraph (3) must be made in a case within sub-paragraph (2)(b). (6) A payment made under sub-paragraph (3) in a case within sub-paragraph (2)(a) must be made before the end of the tax period referred to in sub-paragraph (2). (7) In this paragraph “ UK supply ” means a qualifying supply of goods that is treated as made in the United Kingdom.