c) Procedural expediency and abuse of procedure 

In general, the question whether an amendment is appropriate can only be answered on the basis of its content, i.e. after it has actually been submitted. To refuse any further amendment is only appropriate if it is evident after various unsuccessful amendments that the proprietor is not seriously trying to overcome the objections but is only delaying the proceedings (T 132/92; see also T 623/12 and T 1758/15, which refers to T 246/08).

In T 491/09 the board noted that firstly, due to the direct treatment of the third auxiliary request by the opposition division, instead of returning to written proceedings, a protraction of the proceedings was avoided and the respondent did not benefit from any further delay. Secondly, it was clearly the purpose of oral proceedings that all concerned were aware of the outstanding issues and what positions were taken on them, including those of the opposition division. Not allowing simple further amendments to resolve such issues would clearly run counter to this purpose. The board pointed out that the Guidelines in force at the time (E‑III, 8.7 – 2010 version) made this clear by referring to the fact that if the opposition division found that some patentable subject-matter resulted from a limitation/amendment, it could even inform the proprietor of the fact and allow them an opportunity to submit amended claims thereon (see also in EPC Guidelines E‑III, 8.9 – April 2025 version). In view of the above, the board concluded that while the respondent needed some prompting to finally come up with this request to address the point under discussion, this did not amount to an abuse of proceedings by, nor to/an unwarranted advantage for the respondent.

In T 28/10, the patent proprietor had defended a limited set of claims in the written proceedings but reverted to the claims as granted at the oral proceedings. The opposition division had exercised its discretion not to admit the request on the basis that it considered its late submission to be an abuse of procedure and that the proprietor itself had conceded that it did not meet the Art. 54 EPC requirements. The board could not see any improper exercise of discretion in this.

In T 2385/12, too, the patent proprietor reverted back to the claims as granted during the oral proceedings before the opposition division. The opposition division admitted this request. The board held, that while there may be instances where reverting to the claims as granted at a late stage of opposition proceedings would be seen as an abuse of procedure, the present specific circumstances (Art. 123(2) EPC objection addressed, no evidence of a deliberate attempt to mislead the opponent) indicated this not to be so in this case. The board also did not accept the suggestion that there should be a point at which previous requests were surrendered prohibiting the return to this subject-matter. Providing concrete guidance on when requests could be filed was not foreseen within the EPC, particularly in view of the exercise of discretion provided in Art. 114(2) EPC. It would also be against the general principle that a surrender of a right cannot be presumed. See also T 1770/16.

In T 368/16 the opposition division allowed the proprietor to file various auxiliary requests in the course of the oral proceedings. Its request IVa was however not admitted by the opposition division. The board held that by not admitting request IVa into the proceedings, the opposition division had exercised its power of discretion under R. 116(2) EPC in an unreasonable way and by not applying the proper principles. The request per se was apt to overcome all the objections discussed so far during oral proceedings. Even if inventive step had still to be discussed, its filing could not be considered as an attempt to prolong unnecessarily the proceedings; on the contrary, since request IVa was based on a convergent limitation with respect to request IIIb and on a combination of features derived from the granted claims, it clearly restricted the issues remaining to be discussed. See, similarly, T 222/16.

In T 802/17 the opposition division had given the patent proprietor an opportunity to draft one additional request during the oral proceedings. However, as it then filed only an amended main request, its later request for permission to file amended auxiliary requests too was refused as this would not have been "fair" to the opponent. In the board's view, the presumably underlying considerations of procedural economy had been insufficient to justify this refusal in the circumstances, as the proprietor had been reacting to a new objection under Art. 123(2) EPC, which had been a surprising turn taken in the proceedings and which its amendment had overcome. See also T 756/18 in which the board found that the opposition division had overstepped the limits of its discretion by stating that it would admit only one auxiliary request and rejecting all other auxiliary requests from the outset for no apparent reason; it did not even examine whether the amendments could have overcome all the objections validly raised up to that point without giving rise to any new ones – which might have rendered them admissible. No abuse of procedure or delaying tactic on the part of the appellant was apparent from the file.

In T 879/18 the board held that a patent proprietor should be given an opportunity to amend, if new facts and evidence were admitted as the subject of the proceedings will have changed. In the case in hand, adding detail from the description was, in the board's view, an appropriate response and should have been admitted. Likewise in T 222/16, the board held that the patent proprietor should have been given at least one opportunity to file a new request in response to the new objection filed by the respondent-opponent for the first time on the final date set under R. 116 EPC. On the principles of the right to be heard and the fair treatment of the parties, see also T 487/13 (summarised under chapter IV.C.5.1.6 above) and T 623/12.

In T 1219/19 the appellant asserted that the opposition division had changed its view in the oral proceedings and invoked R. 116(2) EPC to argue that the opposition division had no discretion to disregard the auxiliary request filed after the time limit prescribed in R. 116 EPC or to apply the criterion of prima facie allowability. The board found that the opposition division had exercised its discretion in accordance with the right principles. It could not have been deprived of that discretion merely because it had expressed a different opinion at the oral proceedings from that provisionally set out in the communication accompanying the summons. Moreover, the opposition division's preliminary opinion clearly indicated that those objections were to be the subject of further discussion at the oral proceedings. The preliminary conclusion was expressed in a careful manner and could not be understood as if the opposition division thereby gave up its discretionary power to disregard submissions filed later. A different conclusion would penalise the useful practice of providing a detailed discussion of the relevant issues in preparation for oral proceedings. In the particular circumstances of the case, a different conclusion reached at the oral proceedings by the opposition division departing from its preliminary opinion in the summons could not be regarded as a change of subject of the proceedings.

On the concept of abuse of procedure, see also the decisions relating to the late submission of documents summarised in chapter IV.C.4.5.4, and in particular T 85/18, which held that abuse of procedure implied deliberate misconduct, not merely a lack of diligence.