Explanations relating to aforesaid provisions :
Explanation 1.—For the purposes of clauses (a) and (b), the supply shall be deemed to have been made to the extent it is covered by the invoice or, as the case may be, the payment.
Explanation 2.—For the purpose of clause (b), “the date on which the supplier receives the payment” shall be the date on which the payment is entered in his books of account or the date on which the payment is credited to his bank account, whichever is earlier.