BIM70038 | Cash basis: expenses: capital expenditure: Financial Assets
From HM Revenue & Customs · Business Income Manual
S33A(4)(f) ITTOIA 2005
In calculating the profits of a trade on the cash basis, no deduction is allowed for a financial asset.
A financial asset means any right under or in connection with
a financial instrument
an arrangement that is capable of producing a return that is economically equivalent to a return produced under any financial instrument
An arrangement includes any agreement, understanding, scheme, transaction or series of transactions (whether or not legally enforceable).