Income and Corporation Taxes Act 1988

3 (1) The cash equivalent for any year of the benefit obtained from a loan is—

(a) the amount of interest (calculated in accordance with paragraph 4 or 5 below) which would have been payable for that year had interest at the official rate been payable on the loan, less

(b) the amount of interest actually paid on the loan for that year.

(2) Where an assessment for any year in respect of a loan has been made or determined on the footing that the whole or part of the interest payable on the loan for that year was not in fact paid, but it is subsequently paid, then on a claim in that behalf, the cash equivalent for that year shall be recalculated so as to take that payment into account and the assessment shall be adjusted accordingly.

(3) All the loans between the same lender and borrower for which a cash equivalent falls to be ascertained and which are outstanding at any time, as to any amount, in any year are to be treated for the purposes of this Schedule as a single loan.