2For the purposes of the principal section and this Schedule a deposit is any sum of money paid to a person carrying on a banking business (" a deposit-taker ") on terms—
(a)under which it will be repaid either on demand or at a time or in circumstances agreed by or on behalf of the person who paid the sum and the deposit-taker ; and
(b)which are not, within the meaning of subsection (6) of section 1 of the [1979 c. 37.] Banking Act 1979, referable to the provision of property or services or to the giving of security.