5(1)The amount of chargeable deposits held by a deposit-taker at any material time shall be treated as—
(a)reduced by an amount equal to 60 per cent, of any sum which has been credited in his books to an account held with him (whether or not an account the balance on which constitutes a chargeable deposit) by reference to a cheque or other authority which is then in course of collection by him ; and
(b)increased by an amount equal to 60 per cent, of any sum which has been debited in his books to such an account by reference to a standing order or other authority which is then in course of transmission by him.
(2)In this paragraph " sum" means a sum denominated in sterling.