(1)M1Where any trade, profession or vocation the profits or gains of which are chargeable to tax under Case I or II of Schedule D has been permanently discontinued, and the profits or gains for any period before the discontinuance were computed on a conventional basis, tax shall be charged under Case VI of that Schedule in respect of any sums to which this subsection applies which are received on or after the discontinuance.
(2)Subject to subsection (3) below, subsection (1) above applies to all sums arising from the carrying on of the trade, profession or vocation during any period before the discontinuance, not being sums otherwise chargeable to tax, in so far as the amount or value of the sums was not brought into account in computing the profits or gains for any period before the discontinuance.
(3)In subsection (2) above the reference to sums otherwise chargeable to tax includes any sums which (disregarding this section) are chargeable to tax under section 103 or to which that section would have applied but for subsection (3)(a) and (b) of that section.
(4)M2Where, in the case of any trade, profession or vocation the profits or gains of which are chargeable to tax under Case I or II of Schedule D, there has been—
(a)a change from a conventional basis to the earnings basis, or
(b)a change of conventional basis which may result in receipts dropping out of computation,
tax shall be charged under Case VI of that Schedule in respect of sums to which this subsection applies which are received after the change and before the trade, profession or vocation is permanently discontinued.
(5)Subsection (4) above applies to all sums arising from the carrying on of the trade, profession or vocation during any period before the change, not being sums otherwise chargeable to tax, in so far as the amount or value of the sums was not brought into account in computing the profits or gains for any period.
(6)M3It is hereby declared that where work in progress at the discontinuance of a profession or vocation, or the responsibility for its completion, is transferred, the sums to which subsection (1) above applies include any sums received by way of consideration for the transfer, and any sums received by way of realisation by the transferee, on behalf of the transferor, of the work in progress transferred.
(7)Where in the case of any profession or vocation, the profits or gains of which are chargeable to tax under Case II of Schedule D—
(a)there has been a change from a conventional basis to the earnings basis, or a change of conventional basis, and
(b)the value of the work in progress at the time of the change was debited in the accounts and allowed as a deduction in computing profits for tax purposes for a period after the change,
then, in so far as no counterbalancing credit was brought into account in computing profits for tax purposes for any period ending before or with the date of the change, tax shall be charged under subsection (4) above in respect of that amount for the year of assessment in which the change occurred as if that amount were a sum to which that subsection applies, and the change of basis were a change of the kind described in that subsection.