Where—
(a) a return is amended under section 28A(2)(b), 28B(2)(b) or 28B(4), and
(b) the amendment is made for the purpose of making good to the Crown any loss of tax brought about carelessly or deliberately by the taxpayer or a person acting on his behalf,
sections 36(3) and 43(2) apply in relation to the amendment as they apply in relation to any assessment under section 29.
Where—
(a) a return is amended under section 28A(2)(b), 28B(2)(b) or 28B(4), and
(b) the amendment is not made for the purpose mentioned in subsection (1)(b) above,
sections 43(2), 43A and 43B apply in relation to the amendment as they apply in relation to any assessment under section 29.
References to an assessment in sections 36(3), 43(2), 43A and 43B, as they apply by virtue of subsection (1) or (2) above, shall accordingly be read as references to the amendment of the return.
In subsection (4) above "consequential claim" means any claim, supplementary claim, election, application or notice that may be made or given under section 36(3), 43(2), 43A or 43D(6) (as it applies by virtue of subsection (1) or (2) above or otherwise).