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This chapter discusses the streamlined opposition procedure of the European Patent Office (EPO) and the general trend of the Boards of Appeal towards restricting the appeal process to being a review of the decision at issue rather than an opportunity to present a fresh case. This was codified in the updated Rules of Procedure of the Boards of Appeal, which came into force in January 2020.

The EPO provides an opportunity to file a central opposition against the grant of a European patent within an opposition period of nine months. Opposition proceedings are predominantly written proceedings but typically will conclude with oral proceedings before an Opposition Division of three members. Decisions of the Opposition Division may be appealed to the Boards of Appeal.

The Boards of Appeal of the EPO is an autonomous body, comprising 28 boards that each deal with different subject-matter areas. The Boards of Appeal can exercise any power within the competence of the Opposition Division or remit the case to the Opposition Division for further prosecution.

The opposition procedure at the EPO is used extensively. With such a large number of oppositions being filed, there has been a growing backlog of pending cases. Although it is likely to be a more expensive procedure, the advent of the Unified Patent Court could potentially offer a faster route to revocation of a European patent.

In July 2016, the EPO streamlined the procedure for oppositions, along with a commitment to reduce the duration of the procedure from the expiry of the opposition period until the issuance of a decision by the Opposition Division. The streamlined procedure is intended to reduce the duration of a straightforward case to a maximum of 15 months.

The effect of the covid-19 pandemic has obscured the data; however, it was clear from pre-pandemic data that the streamlined procedure was having the desired effect. In 2016, the average length of time for a straightforward case was approximately 26 months. According to the EPO's Annual Report 2021, the average time to a decision had reduced to 19.3 months. The streamlining of the opposition procedure may, therefore, help to prevent the proposed Unified Patent Court from negatively impacting the number of oppositions filed and may reduce the likelihood of revocation proceedings being run in parallel at both the EPO and the Unified Patent Court.

Recently, there have been changes not only to the opposition procedure, but also to the appeals process. In an effort to enhance the independence of the Boards of Appeal, in June 2016 the Implementing Regulations of the European Patent Convention were amended to allow the Boards of Appeal to be organised as a separate unit within the EPO with its own president who is answerable only to the Administrative Council, the body that oversees the work of the EPO. This was accompanied by the relocation of the Boards of Appeal to Haar, Germany, in October 2017. However, a proposal has been put forward to return the Boards of Appeal to central Munich in 2025-26. The first president of the Boards of Appeal, Carl Josefsson, assumed the role in March 2017.

As with prosecution and opposition cases before the Examining and Opposition Divisions of the EPO, the Boards of Appeal have a significant backlog of cases. In the first annual report of the Boards of Appeal following this organisational change, Josefsson indicated his intention to increase the productivity of the Boards such that within five years, 90 per cent of cases would be settled within 30 months. The initial signs that productivity is increasing are positive, with the number of pending cases reducing from more than 9,000 in 2019 to just over 7,000 at the start of 2022.

The two mechanisms implemented to increase productivity are an increase in resources and 'efficiency measures'. The increase in resources has led to the recruitment of additional technical board members such that the Boards of Appeal now include 196 chairs and members, including 136 technically qualified members capable of carrying out substantive examinations of cases. One of the efficiency measures was the revision of the Rules of Procedure of the Boards of Appeal, discussed below.

The Rules of Procedure of the Boards of Appeal define the appeal process. For an opposition case, this typically involves two rounds of written correspondence followed by oral proceedings. In the first written round, each appealing party files its grounds of appeal: a statement indicating the reasons for setting aside the appealed decision, along with any facts and evidence to be relied upon. A patentee may accompany its grounds of appeal with one or more requests, each request including an alternative set of claims for consideration in the proceedings.

In the second written round, each party files a reply to the other side's grounds of appeal. The grounds of appeal, together with the reply, are intended to form each party's complete case on appeal; however, further submissions will often be made. This may be the case where one party's reply raises a new issue, or when further evidence or prior art becomes available at a later stage. Further submissions may be considered an amendment to the party's case.

The provisions of the Rules of Procedure of the Boards of Appeal that mainly influence practice are those that determine admissibility. The updated Rules of Procedure of the Boards of Appeal provide very similar discretionary powers as the previous version. Case law from the earlier rules, therefore, remains illustrative of how those powers are to be exercised. First, the Boards can hold inadmissible requests, facts, objections or evidence that could have been presented or were not admitted in the opposition proceedings. Second, it is at the Board's discretion whether any amendment to a party's case after it has filed its grounds of appeal or reply is admitted.

These two powers give the Boards great flexibility in deciding how to deal with each case. The case law has developed numerous threads that explore the various issues that may be considered by the Board when exercising its discretion. These include:

  1. the prima facie relevance of the new evidence or request;
  2. whether the admission will raise issues not previously considered;
  3. the age of the patent;
  4. the reasons why the new evidence or request was not filed earlier; and
  5. in the case of new prior art, whether it is more relevant than earlier filed art.

Because the Board's powers are entirely discretionary and there are numerous issues relating to discretion, the Boards of Appeal have varied in how they exercise this discretion; however, there has been a notable and significant recent trend across most Boards towards applying discretionary powers in a more restrictive manner to limit the ability of the parties to develop their case on appeal.

For instance, it has become increasingly likely that parties will be punished for treating the appeal process as a continuation of the opposition proceedings rather than a review of the decision of the Opposition Division. While it is correct that the purpose of an appeal was always intended to be a review of the reasons for the decision, for many years the practice followed by the parties and the Boards was more flexible. As a result of the increasingly strict application of discretion in respect of admissibility, the outcome of an increasing number of cases is being decided on procedural grounds rather than for substantive reasons.

In T156/15, the appellant (patentee) twice filed a new auxiliary request after hearing the Board's decisions in respect of the preceding request. The Board admitted the first, but refused to consider the second, indicating that a request may be found inadmissible because its admission would be unfair to the other party, even if the request is prima facie allowable. In other words, procedural issues can take precedence over substantive issues.

Another case, T1903/13, is illustrative of how far the Boards might take that principle. The respondent (patentee) filed a number of auxiliary requests on appeal that the Boards accepted were essentially already filed during opposition proceedings; however, the requests were not considered by the Opposition Division because a higher-ranking request was allowed. The requests were not convergent with the claims allowed by the Opposition Division, meaning that they were not sequentially narrowed versions of the allowed claims. The Boards, therefore, refused to take the requests into account because to consider them would be to consider inventive concepts that were not the subject of the appeal.

In a similar case, T1280/14, the respondent (patentee) maintained 15 auxiliary requests that had been filed during the opposition procedure but had not been considered. The respondent only intended to pursue two of those requests; however, because the respondent chose not to abandon the other requests in advance of the oral proceedings, those requests were not admitted.

In the past, parties have often used the written opinion of the Boards, where issued, to guide the filing of further requests or to replace requests; however, it is now very clear that parties should not allow a point to be unanswered with the intention of awaiting any written opinion before dealing with the issue. In T1459/11, the Boards stressed that a written opinion is intended to prepare the case for oral proceedings rather than to be an invitation for the parties to make further submissions.

In decision T875/14, the respondent (patentee) filed a request in reply to the Board's views on novelty and inventive step expressed in the written opinion. The Boards noted that the objections were not raised ex officio but had already been presented in the appellant's (opponent's) grounds for appeal; thus, the Boards did not accept that the request filed by the respondent (patentee) was in response to an unexpected development, so the request was not admitted.

In the event that a new request is responsive to an unexpected development, it is necessary for the request to deal with all outstanding issues (Case Law of the Boards of Appeal, 9th Edition, IV, E, 4.12.1). In T416/12, the Boards indicated that it should be possible to establish this with little or no investigative effort on its part.

A recent example of a decision in which an amendment in response to the Board's written opinion was accepted is T32/16. In this case, the Board considered that the relevant elements of the appellant's (opponent's) lengthy arguments had been identified by the Board for the first time in its written opinion. Although those arguments had been put forward by the appellant (opponent) earlier in proceedings, the respondent (patentee) was permitted to amend its main request in view of the immediacy of the response and the fact that the amendments overcame the objection highlighted by the Board without raising new issues.

The restriction of the scope of appeals is not only applicable to patentees; the Boards apply similar approaches to the admission of documents filed late by opponents and to requests filed late by patentees. For example, in T2384/13, the appellant (opponent) was prevented from filing a new prior art document on appeal when it was apparent during opposition proceedings that the objections were not considered convincing in such a way that the appellant should have filed the document earlier.

In T340/12, the Boards considered that if a prior art document is clearly very relevant, it should take precedence over the procedural aspects of its late filing; however, this is not always the case. In T2471/13, the Boards refused to admit a prior art document, irrespective of its relevance, owing to the decision of the appellant (opponent) to withhold it during opposition proceedings.

It is becoming more difficult to raise new attacks, even when the documents used are already in proceedings. In T875/14, the appellant (opponent) attempted to raise a new objection during the oral proceedings that, for the first time, considered inventive step when starting from a prior art document different from that used as the closest prior art in earlier filed attacks. Although that document was already present in the proceedings and was considered to deprive the granted claims of novelty, the argument itself constituted an amendment of the appellant's case.

The argument was not admitted because the request it was raised against was formed from a subset of the granted claims. Despite there being a large number of independent claims in the granted patent, the Boards concluded that the argument should have been raised earlier.

On the other hand, in T1830/11, new evidence was admitted when filed with the appellant's (opponent's) grounds of appeal for use against a request formed by incorporating the subject matter of a dependent claim into claim one. The Boards, in that instance, considered that there was no requirement for an opponent to provide evidence against every possible fallback position in the granted claims.

In case T55/11, a new inventive step objection was raised that combined two documents used in an existing argument; however, the roles of the two documents were switched in the new argument such that the closest prior art document in the new objection was the combination document in the earlier objection. Because the Boards had indicated in their written opinion that the combination of the two documents was to be considered, the patentee could have foreseen the new objection, so the argument was admitted.

Not only should the opponent's intended arguments in respect of the prior art be elaborated at the earliest opportunity but also the patentee's reasons for filing each of the requests. While it may in some cases be immediately evident that the auxiliary requests overcome all outstanding objections, where this is not the case the Boards have argued that requests should only be considered filed on the dates on which they are substantiated.

In T1784/14, a number of the respondent's (patentee's) auxiliary requests were considered inadmissible despite being filed before the Opposition Division and mentioned in the respondent's (patentee's) reply to the grounds for appeal. Because it was not apparent how those requests dealt with the objections against the earlier requests, they were not considered validly filed.

On 1 January 2020, a revised version of the Rules of Procedure of the Boards of Appeal came into force, with the aim of improving the efficiency of the Boards to reduce the time taken to process each case. Although many of the changes to the rules appear to be minor differences in emphasis, when considered in the context of the recent trend towards restricting the parties' scope for changing their case on appeal, it appears likely that the trend will continue. In fact, the new rules set out three levels of convergence. It should be noted that convergence in this context is convergence of the issues to be considered, rather than convergence of the scope of the claims. Each subsequent level of convergence imposes greater restrictions on the parties' freedom to change their cases. Moreover, the restrictions of each level of convergence are applied cumulatively.

For example, in cases considered under the old rules, the Boards are able to find inadmissible facts, evidence or requests that could have been presented, or were not admitted, at first instance. Under the revised rules, however, the default is reversed for the first level of convergence. A Board's power is now to admit requests, facts, objections, arguments and evidence that were not pursued in first instance proceedings. Those aspects of the case must have been both admissibly raised and maintained at first instance. Moreover, under the new rules, the parties are expected to identify any changes to their case on appeal and provide reasons why they were not submitted at first instance. In the case of the patentee, any amendments of the specification should be accompanied by an indication of the basis for the amendments along with an explanation of how they deal with the objections in the decision.

Arguments and objections have been added to the existing list of facts, evidence or requests that define a party's case. Accordingly, it will be necessary to argue in support of the admissibility of new lines of attack or defence presented on appeal. This hurdle of admissibility is now at the level previously set only for amendments of a party's case after filing the grounds of appeal and reply.

The Rules of Procedure of the Boards of Appeal have also been changed to define the second level of convergence in relation to amendments made after the filing of grounds of appeal or the reply to the grounds of appeal of the other party. Under the old rules, any amendments to a party's case on appeal may be admitted at the Board's discretion in accordance with the criteria defined in the case law discussed above. In the updated rules, these developments in the case law have been codified to provide a non-exhaustive list that includes the state of proceedings, the suitability of the changes to resolve the issues of the appeal, procedural economy and, for an amendment of a patent, whether it overcomes the objections raised without raising others.

More notably, the rules have changed to introduce the third level of convergence in respect of amendments to a party's case made after a summons to oral proceedings or the Board's written opinion. Previously, such amendments were inadmissible if the Board or other party could not be expected to deal with them before the oral proceedings. Under the updated rules, the bar is higher; such amendments will only be taken into account if the party can convince the Board that there are exceptional circumstances which justify an amendment of their case at this stage. Whereas for the first two levels of convergence, the Board's discretion is exercised largely in line with the existing case law from before the introduction of the new rules, the definition of exceptional circumstances has been the subject of many new cases. This is because establishing that there are exceptional circumstances justifying an amendment of the party's case is a hurdle that must be overcome before the Board is free to exercise its discretion with respect to the admissibility of the amendment itself. The phrase 'exceptional circumstances' has been construed in a variety of ways in recent case law, but it is becoming clear that unexpected developments in the case can be argued to be exceptional circumstances, while the normal progression of a case cannot. However, some decisions have taken a broader interpretation. In T713/14, the Board took the entire background of the case into consideration in deciding that there were exceptional circumstances. In some cases, it may be that the nature of the amendment will be relevant. In T2920/18, it was decided that the simple deletion of claims justified a finding of exceptional circumstances.

In view of the updated rules, since 1 January 2020, the tasks of preparing a statement of grounds of appeal and the reply to another party's grounds of appeal, in most cases, involves a greater emphasis on the procedural aspects of the case that justify or challenge any change in strategy by the other party. Although the rules have changed in tone, clearly with the intention of restricting the parties' ability to amend, the same element of discretion remains, so it remains to be seen whether the changes will eliminate the wide range of practices among the Boards.

In view of the need to justify on appeal any aspect of the case that has changed since first instance, it is necessary for both parties to take this into consideration when deciding their strategy during opposition.

From the patentee's perspective, the result of the increasingly restrictive approach of the Boards is that the only way for a patentee to be sure that a request may be relied upon on appeal is to ensure that it is filed, and admitted, by the Opposition Division.

Moreover, on appeal, it is now clearly insufficient to merely file arguments in respect of a main request and accompany that with other auxiliary requests without a full discussion of how those additional requests overcome any objections. This may be the case even if they were already filed before the Opposition Division.

To ensure that a set of requests can be defined during opposition that will subsequently be of use when filing an appeal, it may be advantageous to file multiple auxiliary requests along with the patentee's reply to the notice of opposition. In this way, the requests can be considered by the Opposition Division when preparing a summons, and the patentee will have the opportunity to file a refined set of requests in advance of the oral proceedings before the Opposition Division if necessary. That latter set of requests can form the basis of the appeal, perhaps supplemented where appropriate.

For an opponent, it should be remembered that a new line of argument, even if based on the prior art documents relied upon at first instance, may be found inadmissible on appeal. It is often the case that such new lines of argument may occur to an opponent in preparation for oral proceedings. The minutes of the oral proceedings before the Opposition Division can potentially, therefore, become the only record of lines of argument raised at that stage.

The minutes produced by the Opposition Divisions rarely capture all the important details raised. It is, therefore, expected that during oral proceedings parties will increasingly request that new lines of attack be recorded as such. In addition, it is advisable that the minutes be scrutinised more closely and that important errors or omissions be challenged before the appeal is filed.

There have been a number of further changes in the updated Rules of Procedure of the Boards of Appeal, and one in particular is notable. It was previously the case that remittal to the department of first instance would be likely where the parties agreed and where there were unexplored grounds such as novelty and inventive step, or unexplored attacks such as a different combination of prior art documents. The updated rules indicate that the default position of the Boards is now not to remit the case unless there are 'special reasons' for doing so.

The denial of remittal by the Boards of Appeal may be a useful tool for reducing the backlog by preventing cases from being shuttled backwards and forwards between the departments of first instance and the Boards of Appeal. There was initially concern that, contrary to the old practice, the Boards may decide that the updated rules mean that they should, if possible, consider all grounds on appeal, even if those grounds were not decided upon at first instance. However, the early decisions issued under the new rules seem to indicate that there is little change in the Boards' practice in relation to remittal: in so far as the decision of the Opposition Division does not consider grounds of opposition, remittal remains a likely outcome.

Until 2020, it was normal for the opposition and inter partes appeal procedures to conclude at oral proceedings held in person either in Munich, The Hague or, occasionally, Berlin for oppositions, and in Haar for appeals. Hearings by video conference were previously available for ex parte oral proceedings before the Examining Divisions but were not widely used.

The covid-19 pandemic led to the postponement of in-person oral proceedings for several months of 2020 and motivated the EPO to carry out a pilot project for oral proceedings by video conference before the Opposition Divisions, which has been successful. Throughout the first half of 2021, the Opposition Divisions heard more than 350 cases per month. In parallel, the Boards of Appeal have begun to use video conferences for inter partes oral proceedings.

Initially, the parties' consent was required for the use of video conferences for oral proceedings both for opposition and appeal; however, once the reliability of video conference was established, consent was no longer required.

Following a challenge to this change, the Enlarged Board of Appeal considered the question of whether the ability to hold oral proceedings by video conference without the consent of the parties was an infringement of the parties' rights under the European Patent Convention. Although, at the time of writing, the full decision was not available, the Enlarged Board of Appeal issued an order confirming that the use of video conference without the consent of the parties is compatible with the European Patent Convention; however, it limited the context of the ruling to oral proceedings before the Boards of Appeal and at the time of a general emergency that limits the parties' ability to attend in-person hearings. It remains to be established whether a permanent change to video conference for oral proceedings as a default will be possible.

It is anticipated that following the conclusion of the pilot project, the use of video conferencing may possibly become mandatory for straightforward oral proceedings, such as those forming the majority of cases, which do not require the taking of evidence by the hearing of witnesses or the inspection of non-documentary evidence. For pre-grant oral proceedings before the Examining Divisions of the EPO, this has already been made the default.

In conclusion, the recent practice of the EPO in respect of oppositions and appeals has been to more strictly apply the rules to differentiate opposition and appeal procedures. This restriction of the procedure has continued with the updated Rules of Procedure of the Boards of Appeal.


1 James Short and Rohan Setna are partners at Boult Wade Tennant LLP.