Where for any year of assessment rights to work minerals in the United Kingdom are let, the lessor shall, subject to subsection (2) below, be entitled, on making a claim for the purpose, to be repaid so much of the income tax paid by him by deduction or otherwise in respect of the rent or royalties for that year as is equal to the amount of the tax on any sums proved to have been wholly, exclusively and necessarily disbursed by him as expenses of management or supervision of those minerals in that year.

No repayment of tax shall be made under subsection (1) above if, or to such extent as, the expenses in question have been otherwise allowed as a deduction in computing income for the purposes of income tax.

In computing for the purposes of corporation tax the income of a company for any accounting period from the letting of rights to work minerals in the United Kingdom, there may be deducted any sums disbursed by the company wholly, exclusively and necessarily as expenses of management or supervision of those minerals in that period.