(1) Subject to the following provisions of this section, an assessment under section 73, 75 or 76, shall not be made—

(a) more than [4 years]¹ after the end of the prescribed accounting period or importation or acquisition concerned, or

(b) in the case of an assessment under section 76 of an amount due by way of a penalty which is not among those referred to in subsection (3) of that section, [4 years]¹ after the event giving rise to the penalty.

(2) Subject to subsection (5) below, an assessment under section 76 of an amount due by way of any penalty, interest or surcharge referred to in subsection (3) of that section may be made at any time before the expiry of the period of 2 years beginning with the time when the amount of VAT due for the prescribed accounting period concerned has been finally determined.

(2A) Subject to subsection (5) below, an assessment under section 76 of a penalty under section 65 or 66 may be made at any time before the expiry of the period of 2 years beginning with the time when facts sufficient in the opinion of the Commissioners to indicate, as the case may be—

(a) that the statement in question contained a material inaccuracy, or

(b) that there had been a default within the meaning of section 66(1),

came to the Commissioners' knowledge.

(3) In relation to an assessment under section 76, any reference in subsection (1) or (2) above to the prescribed accounting period concerned is a reference to that period which, in the case of the penalty, interest or surcharge concerned, is the relevant period referred to in subsection (3) of that section.

(4) In any case falling within subsection (4A), an assessment of a person (“P”), or of an amount payable by P, may be made at any time not more than 20 years after the end of the prescribed accounting period or the importation, acquisition or event giving rise to the penalty, as appropriate (subject to subsection (5)).

(4A) Those cases are—

(a) a case involving a loss of VAT brought about deliberately by P (or by another person acting on P’s behalf),

(b) a case in which P has participated in a transaction knowing that it was part of arrangements of any kind (whether or not legally enforceable) intended to bring about a loss of VAT,

(c) a case involving a loss of VAT attributable to a failure by P to comply with a notification obligation, and

(d) a case involving a loss of VAT attributable to a scheme in respect of which P has failed to comply with an obligation under paragraph 6 of Schedule 11A.

(4B) In subsection (4A) the references to a loss of tax brought about deliberately by P or another person include a loss that arises as a result of a deliberate inaccuracy in a document given to Her Majesty’s Revenue and Customs by that person.

(4C) In subsection (4A)(c) “notification obligation” means an obligation under—

(a) paragraph 5, 6, 7 or 14(2) or (3) of Schedule 1,

(b) paragraph 3 of Schedule 2,

(c) paragraph 3 or 8(2) of Schedule 3,

(d) paragraph 3, 4 or 7(2) or (3) of Schedule 3A, or

(e) regulations under paragraph 2(4) of Schedule 11.

(5) Where, after a person’s death, the Commissioners propose to assess a sum as due by reason of some conduct (howsoever described) of the deceased, including a sum due by way of penalty, interest or surcharge—

(a) the assessment shall not be made more than [4 years]¹ after the death; ...²

(b) ...²

(6) If, otherwise than in circumstances falling within section 73(6)(b) or 75(2)(b), it appears to the Commissioners that the amount which ought to have been assessed in an assessment under that section or under section 76 exceeds the amount which was so assessed, then—

(a) under the like provision as that assessment was made, and

(b) on or before the last day on which that assessment could have been made,

the Commissioners may make a supplementary assessment of the amount of the excess and shall notify the person concerned accordingly.