How much priority for entitlement to priority?

C. Rennie-Smith

The latest referral to the Enlarged Board of Appeal was made only (as of the date I write this) one month ago. In a decision issued on 28 January 2022 in consolidated cases T 1513/17 and T 2719/19The cases were consolidated because they had parties in common and the same issues were raised in both cases, albeit one was an examination appeal and the other an opposition appeal. The referrals are now pending before the Enlarged Board under the numbers G 1/22 and G 2/22. References below to “Point X” are to the reasons of the referring decision., Board 3304 referred two questions to the Enlarged Board about entitlement to priority under Article 87 EPC. The questions read:

I. Does the EPC confer jurisdiction on the EPO to determine whether a party validly claims to be a successor in title as referred to in Article 87(1)(b) EPC?

II. If question I is answered in the affirmative

Can a party B validly rely on the priority right claimed in a PCT-application for the purpose of claiming priority rights under Article 87(1) EPC in the case where

1) a PCT-application designates party A as applicant for the US only and party B as applicant for other designated States, including regional European patent protection and

2) the PCT-application claims priority from an earlier patent application that designates party A as the applicant and

3) the priority claimed in the PCT-application is in compliance with Article 4 of the Paris Convention?

I shall comment here on the key issue raised in the second question (which the referring Board calls the "PCT joint applicants approach") and the general issue raised in the first question which to my mind poses unnecessary problems.

The “PCT joint applicants approach”

We are all familiar with the fundamental provision for determining priority entitlement under Article 87(1) EPC - the later European application must be filed by the same person who filed the earlier priority application or, provided evidence of a transfer can be shown, his successor in title. It has also always been the case that additional applicants for the European application are permitted provided the earlier applicant(s) or his/her successor(s) is (or are) also present as applicants. The Guidelines have, for several editions, summarised this thus:

However, in the case of joint applicants filing the later European patent application, it is sufficient if one of the applicants is the applicant or successor in title to the applicant of the previous application. There is no need for a special transfer of the priority right to the other applicant(s), since the later European application has been filed jointly. The same applies to the case where the previous application itself was filed by joint applicants, provided that all these applicants, or their successor(s) in title, are amongst the joint applicants of the later European patent application“Guidelines for Examination in the European Patent Office”, March 2021 edition, Part A, Chapter III, section 6.1, page III-8.

This passage includes several uses of the words “joint applicants” which is (or should I say, was?) a good description of a principle which allowed the original applicant or successor to be joined by other applicants in the later application. The important point was that there had to be identity of applicant(s) between the earlier (priority providing) application and the later (priority claiming) European application.

However, as we have recently become aware, some EPO examiners have stretched this principle to cover cases where there is not complete identity between the two sets of applicants in as much as the later (European) application stems from a PCT filing - typically, if not always, claiming a US priority - in which the original applicant(s), who in the USA were usually the inventors, reappear as applicants for the USA only and another party - typically, the inventors' employer - appears as the applicant for other jurisdictions including the EPO. This fact situation has been allowed in a number of first instance decisions as complying with Article 87 EPC and the Guidelines mentioned above because all the earlier and later applicants appear in the PCT application, though not for the same jurisdictions, and are therefore treated as "joint applicants". And, rather confusingly, the expression "joint applicants approach" has recently been used to mean, or to include, this fact situation. Helpfully, the referring board has now suggested calling it the "PCT joint applicants approach".

My reason for calling this application of the principle outlined above "stretched" is that it allows priority to be claimed in a situation where there is no identity of applicant(s) between the earlier (priority providing) application and the later (priority claiming) European application. The only connection between the earlier and later applicants is that they all appear on the same PCT application but in different capacities. In my view that is not consistent with the wording of Article 87(1) EPC which requires that the same person or his successor in title has filed both the earlier application and the later European application.

It appears that the referring board also had only limited enthusiasm for the "PCT joint applicants approach". In points 28 to 41 of its referring decision the board describes three possible legal bases for the approach which were raised in oral proceedings before it. The first and second were said to be respectively not convincingPoint 31 and without meritPoint 33.

The first argumentPoints 30-31 proceeded from Article 11(3) PCT which provides that an international application shall have the effect of a regular national application in each designated state and which has a mirror provision in Article 153(2) EPC. Then one turns to Article 118 EPC which provides that, where the applicants for a European patent are not the same in respect of different designated Contracting States, they shall be regarded as joint applicants for the purposes of EPO proceedings. However, the board pointed to the differences between European and PCT applications and observed that the possibility of designating different PCT applicants for different designated States necessarily mean that the status as an applicant is limitedPoints 32-33 to the designated territories. As I commented above, the only connection between the earlier and later applicants is that they all appear on the same PCT application but in different capacities.

The second argument was that the PCT joint applicants approach can be based on the unitary character of the priority right in the PCT and thus on the operation of the PCT alone. The referring board disliked this because the PCT does not create its own rules regarding the effect of a priority claim but refers to Article 4 of the Paris Convention (which of course is the "ancestor" of Article 87 EPC). Thus, the validity of the PCT joint applicants approach should be assessed in the light of the Paris Convention, in particular the meaning of "successor in title", rather than the PCT. As I commented above, Article 87(1) (and the Paris convention) require the same person or his successor in title to be applicants for both the earlier application and the European application which is inconsistent with the earlier applicant remaining applicant for the USA and another applicant becoming the applicant for Europe - unless of course he is the successor in title to the earlier applicant.

The third argumentPoints 34-41 was based on a national decisionGerechtshof Den Haag 30 July 2019, ECLI:NL:GHDHA:2019:1962 in which the Court of Appeal of The Hague had held that the right to priority should be determined in accord with the national law of the country granting or nullifying patents. In the case of a European patent, that law would be the EPC. Since the EPC has no particular formalities for transfer of the right to priority, proof of an agreement to transfer would be enough. While the referring board clearly liked this third argument more than the other two (it seemed "appealing"Point 37), it observed that the Boards of Appeal have in several cases assessed the transfer of priority right (in other words, whether or not succession in title has been established) by applying national lawAnd, I would add, also on occasion after first deciding which of two (or more) national laws should apply.. If The Hague court approach was to be followed then, because the EPC has no formal requirements, it could be argued that the filing of a PCT application by A and B, in which B is named as applicant for a European patent and A (who was entitled to the priority) as applicant for the USA, demonstrates an implied agreement to transfer the priority right for Europe from A to BThe referring board also saw some measure of support for this in two other national decisions (one German, one English) which will be familiar to followers of priority issues - BGH 16 April 2013 case X ZR 49/12 (Fahrzeugscheibe) and KCI Licensing Inc and others v. Smith & Nephew PLC and others [2010] EWHC 1487 (Pat) 23 June 2010.

While the third argument is certainly more appealing than the other two, there are two major reasons for hoping the Enlarged Board is unpersuaded by it. First, as the referring board says, Boards of Appeal already make priority entitlement decisions using national law. And not just Boards of Appeal, Opposition Divisions must make such decisions and both instances are now experienced in applying the relevant case law. It is without doubt an exclusively legal issue but boards have a legally qualified member and Opposition Divisions can and do add an additional legal member for such issues. If, as I have heard suggested by critics of the EPO, the PCT joint applicants approach has been conceived by first instance management as a simple way of resolving priority entitlement issues relating, for the most part, to Euro-PCT applications claiming priority from US applications, then that is an unfair reflection on the ability of Opposition Divisions to handle legal issues.

Second, if the PCT joint applicants approach were to be blessed by the Enlarged Board, we might see an unwelcome number of cases in which it is argued that dubious priority entitlement can be resolved by alleged implied agreements. That would not be any easier to deal with than the present "succession in title" cases. The fact is that, while we have no requirements in the EPC for the assessment of entitlement to priority, we have already made good that absence of requirements with a workable approach contained in reliable case law.

The First Question

The attitude of the referring board to the PCT joint applicants approach seems to be negative which suggests that the referral may have been made in order to stifle the approach before it gains more currency. However, the first question which the board has added as a preamble - whether the EPO has jurisdiction to determine a party's claim to be a successor in title - seems distinctly problematic. Three comments.

First, the referring board's reasons for including this question seem less than convincing. Two of the three parties before the board had proposed questions whether the EPO has jurisdiction to examine the entitlement to or validity of a priority claim but in the limited context of Euro-PCT applications. The referring board observes that the jurisdiction issue had already been addressed extensively in T 844/18, that in that case it was held that there is no legal basis to relieve the EPO from the obligation to make the assessment required by Article 87(1) EPC, and that it (the referring board) is inclined to agree with that conclusionPoint 24. It further observed that there had been no explicit question of jurisdiction in its written proceedings and no challenge to T 844/18 other than a reference to J 11/95 which it found unconvincingPoint 25. In J 11/95 the issue was mentioned obiter and without reasons..

So why did the referring board none the less decide to question what it called the "standing practise of the boards of appeal to decide on the priority rights in general, including the entitlement to the priority right"Point 24? The answer appears to be because the jurisdiction issue will "in spite of the decision in case T 844/18, most likely be raised again in other cases"Point 26. With respect to the board, this is as unconvincing as the other arguments they called as much. While they mentioned jurisdiction had been questioned in other cases and commentaries, those cases were decided without the need for referral and only one commentary is actually mentioned. The referring board's conclusionIbid is then

"The board is also receptive to the argument of the parties that, if questions regarding priority are to be referred to the EBA on a related matter, this is a convenient opportunity to have a final decision on the "jurisdiction issue" as well. The board therefore decides to include a question addressing the jurisdiction of the EPO to decide on the entitlement to the priority right."

We should ask since when, and on what authority, has "convenient opportunity" been an appropriate basis for referring questions to the Enlarged Board?
Second, the very description of the jurisdiction issue by the referring board prompts the question whether the first question is admissible or not. If the matter has been extensively examined and decided already in a manner which has not been convincingly challenged in the cases before the board, if earlier cases have been decided without a referral, and if the question is the subject of "standing practice", why does the referring board need the opinion of the Enlarged Board to decide the cases before it? Is there a need to ensure uniform application of the law or a point of law of fundamental importance as required by Article 112(1) EPC? As the referring board itself says (of the PCT joint applicants approach), it is appropriate to only refer questions that are relevant for the decision in a given casePoint 27. A "convenient opportunity" does not meet that criterion.

Third, let us consider for a moment the possibility that the Enlarged Board should answer the first question in the negative. The second, and clearly relevant and otherwise admissible question about the PCT joint applicants approach, which is prefaced with the words "[i]f question I is answered in the affirmative", might then go undecided or, if decided, at best answered with an opinion which might be considered obiter. Fortunately (or should I say hopefully?), the very reasons why the first question need not be referred should lead the Enlarged Board to answer it clearly and emphatically "yes".

Christopher Rennie-Smith was previously a legally qualified member of the Boards of Appeal and Enlarged Board of Appeal and from 2010 to 2014 chairman of Technical Board of Appeal 3304. He is now a consultant. He can be contacted at