A fee that has been validly paid (see A‑X, 7.1.1) is not refunded. For instance, a validly paid further processing fee is not refunded if the request for further processing is rejected due to non-completion of the omitted act, which is another requirement of Rule 135(1) (see E‑VIII, 2). As an exception to this general principle, a validly paid fee is refunded if there are special provisions for the refund in either the EPC or the Rules relating to Fees (see A‑X, 2).
By contrast, any fee which has not been validly paid is to be refunded. See subsections A‑X, 10.1.1 to A‑X, 10.1.3 below.