ITO Section 67

Apportionment of deductions.

(1) Subject to this Ordinance, where an expenditure ["expenditures, deductions and allowances"] relates to –

(a) the derivation of more than one head of income; or
(b) the derivation of income comprising of taxable income and any class of income to which sub-sections (4) and (5) of section 4 apply, or;
(c) the derivation of income chargeable to tax under a head of income and to some other purpose,
the expenditure ["expenditures, deductions and allowances"] shall be apportioned on any reasonable basis taking account of the relative nature and size of the activities to which the amount relates.

(2) The [Board] may make rules under section [237] for the purposes of apportioning deductions ["expenditures and allowances"].