This section applies for calculating the amount of income charged under this Chapter.

Expenses wholly and exclusively incurred for the purpose of generating the income are deductible.

If an expense is incurred for more than one purpose, a deduction may be made for any identifiable part or identifiable proportion of the expense which is incurred wholly and exclusively for the purpose of generating the income.

Expenses which would not have been allowable as a deduction in calculating the profits of a trade, if they had been incurred for its purposes, are not deductible under this section.

Expenses for which any kind of relief is given under any other provision of the Income Tax Acts are not deductible under this section.

Any relief given as a result of section 613 is additional to the relief under this section.