6(1)Sections 86 and 88(1), (4) and (5)(a) and (b) of the Taxes Management Act 1970 (interest on amounts overdue, and on tax recovered to make good loss due to taxpayer’s fault) shall apply in relation to any amount due in respect of Class 4 contributions as they apply in relation to income tax; and section 824 of the Act of 1988 (repayment supplements) shall, with the necessary modifications, apply in relation to Class 4 contributions as it applies in relation to income tax.
(2)The Inland Revenue shall have the same powers under section 1 of the Taxes Management Act 1970 (general functions of care and management) in relation to the remission of interest payable under section 86 or 88 of that Act by virtue of this paragraph as they have in relation to the remission of interest payable under either of those sections on tax.
7Where an assessment has become final and conclusive for the purposes of income tax for any year, that assessment shall also be final and conclusive for the purposes of computing liability for Class 4 contributions; and no allowance or adjustment of liability, on the ground of diminution of income or loss, shall be taken into account in computing profits or gains chargeable to Class 4 contributions unless that allowance or adjustment has previously been made on an application under the special provisions of the Income Tax Acts relating to it, or falls to be allowed under paragraph 3(5) of this Schedule.
8The provisions of Part V of the [1970 c. 9.] Taxes Management Act 1970 (appeals, etc.) shall apply with the necessary modifications in relation to Class 4 contributions as they apply in relation to income tax; but nothing in the Income Tax Acts shall apply with respect to the determination of any question arising—
(a)under subsection (1) of section 17 above or subsection (1) of section 17 of the Northern Ireland Contributions and Benefits Act as to whether by regulations under that subsection a person is excepted from liability for Class 4 contributions, or his liability is deferred; or
(b)under regulations made by virtue of section 17(3) or (4) or 18 above or section 17(3) or (4) or 18 of the Northern Ireland Contributions and Benefits Act.