If fees have not been validly paid they must be refunded. Examples: filing fee, search fee, designation fees or examination fee paid late, as laid down under the provisions relating to further processing (Art. 121 and Rule 135), without the further processing fee required by Rule 135(1) and Art. 2, No. 12 RFees. Fees paid on or after the due date are refunded only if there is a particular reason for a refund (see XI, 10.2).