5(1)This paragraph applies if—
(a)a person is entitled to obtain an amount by way of repayment or drawback in respect of excise duty paid to the Commissioners,
(b)on or after the commencement day he makes a claim for the repayment or drawback,
(c)the Commissioners set off the amount against an assessment,
(d)the assessment is withdrawn, and
(e)the Commissioners authorise the repayment or drawback.
(2)The Commissioners must pay interest to the person on the amount for the applicable period.
(3)The applicable period is the period which—
(a)starts with the earlier of the days referred to in sub-paragraph (4), and
(b)ends with the day when the Commissioners authorise the repayment or drawback.
(4)The days are—
(a)the day the amount is set off;
(b)the day after the end of the period of 30 days starting with the day on which the Commissioners receive the claim.
(5)Sub-paragraphs (3) and (4) are subject to paragraph 6.