When the fees are increased, the date of payment is set as the relevant date for determining the amount of the fees (cf. Art. 2 of the Decision of the Administrative Council dated 5 June 1992, OJ 7/1992, 344). Setting the date of payment as the relevant date makes it unnecessary as a rule to ascertain the actual due date for determining the amount of the fee. Fees cannot validly be paid before the due date (with the exception of renewal fees - see XI, 4.1.1). Thus, for example, the fees for grant and printing cannot be validly paid in advance before notification of the communication under Rule 51(4).