719. When payment of income tax is due.

The difference between the amount of income tax and capital gains tax contained in a person's self-assessment1 for any year of assessment and the aggregate of:


    (1)     any payments on account made by him in respect of that year2; and


    (2)     any income tax which in respect of that year has been deducted at source3,

is payable by him or (as the case may be) repayable to him4.

Any amount of income tax or capital gains tax which is payable by virtue of an assessment