(1) The tax under Cases I and II of Schedule D shall be charged without any deduction other than is allowed by the Tax Acts.

(2) Subject to the Tax Acts, in computing the amount of the profits or gains to be charged to tax under Case I or II of Schedule D, no sum shall be deducted in respect of-

(a) any disbursement or expenses, not being money wholly and exclusively laid out or expended for the purposes of the trade or profession;

(b) any disbursements or expenses of maintenance of the parties, their families or establishments, or any sums expended for any other domestic or private purposes distinct from the purposes of such trade or profession;

(c) the rent of any dwelling house or domestic offices or any part of any dwelling house or domestic offices, except such part thereof as is used for the purposes of the trade or profession, and, where any such part is so used, the sum so deducted shall be such as may be determined by the inspector and shall not, unless in any particular case the inspector is of the opinion that having regard to all the circumstances some greater sum ought to be deducted, exceed two-thirds of the rent bona fide paid for that dwelling house or those domestic offices;

(d) any sum expended for repairs of premises occupied, or for the supply, repairs or alterations of any implements, utensils or articles employed, for the purposes of the trade or profession, over and above the sum actually expended for those purposes;

(e) any loss not connected with or arising out of the trade or profession;

(f) any capital withdrawn from, or any sum employed or intended to be employed as capital in, the trade or profession;

(g) any capital employed in improvements of premises occupied for the purposes of the trade or profession;

(h) any interest which might have been made if any such sums as aforesaid had been laid out at interest;

(i) any debts, except bad debts proved to be such to the satisfaction of the inspector and doubtful debts to the extent that they are respectively estimated to be bad and, in the case of the bankruptcy or insolvency of a debtor, the amount which may reasonably be expected to be received on any such debts shall be deemed to be the value of any such debts;

(j) any average loss over and above the actual amount of loss after adjustment;

(k) any sum recoverable under an insurance or contract of indemnity;

(l) any annuity or other annual payment (other than interest) payable out of the profits or gains;

(m) any royalty or other sum paid in respect of the user of a [patent;]¹

[(n) without prejudice to the preceding paragraphs any consideration given for goods or services, or to an employee or director of a company, which consists, directly or indirectly, of shares in the company, or a connected company (within the meaning of section 10), or a right to receive such shares, except to the extent-

(i) of expenditure incurred by the company on the acquisition of the shares at a price which does not exceed the price which would have been payable, if the shares were acquired by way of a bargain made at arm's length, ...²

(ii) where the shares are shares in a connected company, of any payment by the company to the connected company for the issue or transfer by that company of the shares, being a payment which does not exceed the amount which would have been payable in a transaction between independent persons acting at arm's [length,or]³]⁴

[(iii) of other-

(I) expenditure incurred, or

(II) payment made to the connected company,

by the company in connection with the right to receive such shares which is incurred or, as the case may be, made for bona fide commercial purposes and does not form part of any scheme or arrangement of which the main purpose or one of the main purposes is the avoidance of liability to income tax, corporation tax or [capital gains tax;]⁵]⁶

[(o) any sum paid or payable under any agreement or understanding whereby a person is obliged to make a payment to a connected person resident in any territory outside the State for an adjustment made, or to be made, to the profits of the connected person for which relief may be afforded under the terms of an arrangement entered into by virtue of subsection (1) or (1B) of section 826, or for a similar adjustment made to the profits of a connected person resident in [a territory in respect of which there are not for the time being in force any arrangements providing for such relief.]⁷]⁸

(3)(a) In respect of a company-

(i) interest payable by the company, and

(ii) expenditure on research and development incurred by the company,

shall not be prevented from being regarded for tax purposes as deductible in computing profits or gains of the company for the purposes of Case I or II of Schedule D by virtue only of the fact that for accounting purposes they are brought into account in determining the value of an asset.

(b) Any amount shall not be regarded by virtue of paragraph (a) as deductible in computing profits or gains of a company for the purposes of Case I or II of Schedule D for an accounting period to the extent that-

(i) a deduction has been made in respect of that amount in computing such profits or gains for a previous accounting period, or

(ii) the company has benefited from a tax relief under any provision in respect of that amount for a previous accounting period