(1) A "quasi-loan" is a transaction under which one party ("the creditor") agrees to pay, or pays otherwise than in pursuance of an agreement, a sum for another ("the borrower") or agrees to reimburse, or reimburses otherwise than in pursuance of an agreement, expenditure incurred by another party for another ("the borrower") -
(a) on terms that the borrower (or a person on his behalf) will reimburse the creditor; or
(b) in circumstances giving rise to a liability on the borrower to reimburse the creditor.
(2) Any reference to the person to whom a quasi-loan is made is a reference to the borrower.
(3) The liabilities of the borrower under a quasi-loan include the liabilities of any person who has agreed to reimburse the creditor on behalf of the borrower.