This section applies if the tenant under the taxed lease has become entitled, in respect of expenditure on the acquisition of an interest in the land subject to the taxed lease, to an allowance for an accounting period under Part 5 of CAA 2001 (mineral extraction allowances) in respect of expenditure falling within section 403 of that Act (qualifying expenditure on acquiring a mineral asset).

If the allowance is in respect of the whole of the expenditure, no deduction is allowed for expenses under section 63 for a qualifying day falling within that or a later accounting period.

If the allowance is in respect of only part of the expenditure (“the allowable part”) the amount of the deduction for expenses under section 63 for a qualifying day falling within that or a later accounting period is calculated by multiplying the amount that, apart from this section, would be the amount of the deduction for the qualifying day by—

$\frac{\mathrm{WE}-\mathrm{AP}}{\mathrm{WE}}$

where—

WE is the whole of the expenditure, and

AP is the allowable part of the expenditure.