CA50370 | MEA: Qualifying expenditure: Interaction with premium relief
From HM Revenue & Customs · Capital Allowances Manual
Where a person incurs capital expenditure on a mineral asset, which is or includes an interest in land, and relief has been allowed under ITTOIA/S60 to S67 and ICTA88/S87 and S87A (premiums), the amount of qualifying expenditure on the acquisition of a mineral asset is reduced proportionately according to the formula at CAA01/S406 (2).