(1)This section applies in any case where a person is entitled to an allowance or relief for a year of assessment and—
(a)he and the inspector have come to an agreement, in writing, as to the extent to which the allowance or relief is to be given effect in that year (whether by deduction from profits or gains or by discharge or repayment of tax, or both); and
(b)no assessment giving effect to the allowance or relief is made for that year.
(2)In a case to which this section applies the allowance or relief shall be taken to have been given effect in the year of assessment in question, as if an assessment had been made, to the extent set out in the agreement mentioned in subsection (1) above.
(3)In this section—
" allowance " means an allowance to which section 70 or 71 of the [1968 c. 3.] Capital Allowances Act 1968 applies (income tax allowances in taxing a trade); and
" relief " means a relief to which Part II of Schedule 9 to the [1981 c. 35.] Finance Act 1981 applies (income tax: stock relief).
(4)This section has effect in relation to agreements made on or after 6th April 1982.