456U.K.In Chapter 3 of Part 4 after section 401 insert—
(1)If an officer of Revenue and Customs discovers that a payment or set-off of tax credit should not have been made or is excessive, the officer may act in accordance with subsection (3) or (4).
(2)For the purposes of subsection (1) it does not matter whether the payment or set-off was excessive when made or became so later.
(3)The officer may make any assessment that in the officer's judgement is needed to recover—
(a)any income tax that should have been paid, or
(b)any payment of tax credit that should not have been made.
(4)More generally, the officer may make any assessment that in the officer's judgement is needed to secure that the liabilities to income tax (and any liabilities to interest on income tax) of the persons concerned are what they would have been if only the correct set-offs and payments had been made.
(5)TMA 1970 applies to an assessment under this section for recovering a payment of tax credit, or of interest on a tax credit—
(a)as if it were an assessment to income tax for the tax year in respect of which the payment was claimed, and
(b)as if the payment represented a loss of tax to the Crown.
(6)Any sum charged by an assessment such as is mentioned in subsection (5) is due within 14 days after the notice of assessment is issued.
(7)The duty to comply with subsection (6) is subject to any appeal against the assessment.”