According to established case law it is clear from the wording of Art. 12(4) RPBA 2007 that the board in inter partes proceedings has discretion over whether or not to admit requests which could have been presented by the patent proprietor in first-instance proceedings, but were not. The precondition of whether the request at issue could have been presented in the first-instance proceedings relates to the question of whether the presenting party could have been expected to present its request in the first-instance proceedings in the circumstances of the specific case (T 1538/10).

In T 240/04, the board refused to consider the third auxiliary request because the appellant could have submitted it before the opposition division. Indeed, it even ought to have done so because the amended independent claim concerned a technical problem which was only remotely related to the original one and presented facts not previously examined. The appellant therefore had to expect that the board would be unable to decide the matter. To admit a new request in those circumstances would practically give patentees the opportunity to compel a remittal to the department of first instance as they pleased, which would not only put the opponent at a disadvantage but would also run counter to the principle of procedural economy.

In T 339/06, the patent granted comprised several independent claims in the same category. The board found that the new request might force it to give in the appeal proceedings a first ruling concerning only subject-matter relating to a fundamentally different embodiment from those which had been the subject of the opposition division's decision. Thus, in particular, the admissibility of a request first submitted in appeal proceedings and relating solely to an independent claim which, although within the scope of the opposition, had not been considered in the first-instance decision had to be decided on in the light of whether it could also have been submitted earlier (see also similar case T 38/13).

In T 1705/07 the appellant for the first time in the appeal proceedings submitted requests which no longer contained the process claims on which the contested decision was based, but which now only comprised claims of another category, namely product and use claims. The board found that the auxiliary requests submitted for the first time in the appeal proceedings related to fundamentally different subject-matter. Consequently, admitting them into the proceedings would mean that the matters in dispute were fundamentally different from both a substantive and a patent-law point of view, so that the upshot would normally be a remittal to the department of first instance. As a result, the proceedings would last longer and the public would be deprived of legal certainty regarding the validity of the contested patent, which would not be compatible with the principle of procedural economy. If these claims were to be discussed and decided upon in the appeal proceedings, that would enable the appellant to make good this omission – for which it itself bore responsibility – solely for its own benefit. In accordance with the legal principle "nemo auditur propriam turpitudinem allegans", however, it was not permissible for any party, in this case the appellant, to benefit from an omission of its own, since this would be unjust to the opposing parties.

In T 1125/10 the appellant had not reacted to the obviously relevant documents filed shortly before the oral proceedings before the opposition division and had not attended those proceedings. The board held that it was the appellant's total inaction in the face of obviously relevant new documents which had prevented the opposition division from taking a reasoned decision on the subject-matter of the amended claims based on those documents, meaning that, even though the appellant had again chosen not to attend the proceedings, it now had to decide on the matter at first and final instance or remit the case to the department of first instance. The board therefore decided not to admit the appellant's new requests into the proceedings (see T 1067/08).

In T 379/09 the patent proprietor filed, only one month before the oral proceedings before the board of the appeal, a new request aimed at overcoming an objection raised by the opposition division, although the nature of the objection had been set out in the summons to oral proceedings issued by the opposition division. Furthermore, admitting the request would have caused a considerable delay of the procedure.

In T 936/09 the board stated that under the EPC, there is no legal obligation for the patent proprietor to take an active part in opposition proceedings. However, the patent proprietor is not free to present or complete his case at any time that he wishes during the opposition or opposition appeal proceedings, depending, for example, on his procedural strategy or his financial situation. If a patent proprietor chooses not to respond in substance at all to the opposition, for example by filing arguments or amended claims, or chooses not to complete his submissions at the stage of the first-instance proceedings, but rather presents or completes his case only in the notice of appeal or the statement setting out the grounds of appeal, then he will need to face the prospect of being held to account for such conduct by the board when, for example, exercising its discretion under Art. 12(4) RPBA 2007. This applies in particular if, as in the present case, all the reasons for revocation of the opposed patent were known to the patent proprietor before it received the impugned decision.

In T 1335/14, the board noted that the case before it was comparable to that in T 936/09 in that, although the patent proprietor had not said that it was not going to respond to the notice of opposition, its failure to take any action over a long period, even though the EPO had sent communications, could objectively only be regarded in the same way.

Likewise in T 1400/11 the appellant (patent proprietor) had not reacted to the opposition filed against its patent, despite having been made aware of all the reasons ultimately leading to its revocation, and had only mounted a defence on appeal. Its approach amounted to circumventing the opposition proceedings in an attempt to shift the whole case to the appeal stage and compel the board to give a first ruling or remit the case to the opposition division. This would also have put the respondent at an unfair disadvantage: if the appellant's main request were admitted and decided upon by the board, the respondent would in effect be deprived of the opportunity to have the matter reviewed at two instances. Since the appellant had not submitted an admissible request on which to base the appeal proceedings, the appeal was dismissed.

In T 23/10 the board stated that a patentee withholding claim requests in opposition proceedings is precluded from having those requests admitted on appeal, since the patentee would otherwise be permitted to disadvantage the adverse parties by conducting appeal proceedings contrary to its actions before the opposition division (endorsed in R 13/11).

Following the decision in T 23/10, the board in T 1165/10 found that, since the patent proprietors could, in the knowledge of the objections of the opponents and the opinion of the opposition division, have submitted further requests in the first‑instance proceedings but had deliberately refrained from doing so, the introduction of new requests during appeal proceedings could only be seen as an attempt to start the opposition anew, which amounted to a clear abuse of procedure.

In T 872/09 none of the patentee's auxiliary requests was admitted into the proceedings because it had deliberately chosen not to defend any of them during the first-instance opposition proceedings, even though it was aware that the opposition division had found its main request unallowable.

In T 301/11 the board stated that the fact that no auxiliary request was filed in opposition proceedings after time had been requested by and allotted to the appellant could only be seen as a deliberate choice not to have any further request decided upon by the opposition division on any other issue (see also T 144/09). The appellant had thereby deliberately prevented a decision of the opposition division on the other grounds of opposition.

In T 2154/13 the board considered that non-attendance at oral proceedings before the opposition division did not in itself justify the submission of new requests in appeal proceedings as a (presumed) reaction to the course of the oral proceedings in which the submitting party deliberately did not participate.