No. 21. Income Tax. 1967. (b) where the income includes a dividend and under the arrangements foreign tax not chargeable directly or by deduction in respect of the dividend is to be taken into account in considering whether any, and if so what, credit is to be given against tax in respect of the dividend included in the income shall be increased by the amount of the foreign tax which falls to be taken into account in computing the amount of the credit; but notwithstanding, anything in this Ordin- ance a deduction shall be allowed of any amount by which the foreign tax in respect of the income exceeds the credit therefore. (5) Paragraph (a) of the preceding subsection (but not the remainder thereof) shall apply to the computation of total income for the purposes of determining the rate of tax men- tioned in section 90 (4). (6) Where- (a) the arrangements provide, in relation to dividend of some classes but not in relation to dividends of other classes, that foreign tax not chargeable directly or by deduction in respect of dividends is to be taken into account in considering whether any, and if so what, credit is to be given against tax in respect of the dividends; and (b) a dividend is paid which is not of a class in relation to which the arrangements so provide, then if the dividend is paid to a company which controls, directly or indirectly not less than one half of the voting power in the company paying the dividend, credit shall be allowed as if the dividend were a dividend of a class in relation to which the arrangements so provide. (7) Credit shall not be allowed under the arrangements against tax chargeable in respect of the income of any person for any year of assessment if he elects that credit shall not be allowed in the case of his income for that year. Time limit 93. (1) Any claim for an allowance for relief or by way for claims, of credit shall be made not later than six years after the end of the year of assessment and in the event of any dispute as to the amount allowable the claim shall be subject to objection and appeal in like manner as an assessment.