11 October 2023

EPO relaxes its approach to ‘same applicant’ priority

The Enlarged Board of Appeal has just issued its decision in consolidated cases G 1/22 and G 2/22 concerning the EPO’s competence to determine ‘same applicant’ priority issues and the assessment of priority in a PCT application (see our earlier coverage here and here).  The decision seems to mark a dramatic relaxation of the EPO’s approach to same-applicant priority, and thus it is strongly pro-applicant/patentee.

First question

The Enlarged Board was asked to answer two questions, the first of which it rephrased thus:

Is the EPO competent to assess whether a party is entitled to claim priority under Article 87(1) EPC?

The question was answered as follows:

The European Patent Office is competent to assess whether a party is entitled to claim priority under Article 87(1) EPC.

There is a rebuttable presumption under the autonomous law of the EPC that the applicant claiming priority in accordance with Article 88(1) EPC and the corresponding Implementing Regulations is entitled to claim priority.

The first part of the answer does not change current practice: the EPO can continue to assess all aspects of the right of priority.  The Enlarged Board held that priority rights are autonomous and that their creation, existence and effects are governed only by the EPC and Paris Convention.  A contrast was drawn in this regard with entitlement to a European application, which is governed by national laws and assessed by national courts.  The Enlarged Board further recognised the importance of comprehensively assessing patentability, which would only be possible if the EPO has the power to assess priority entitlement.  

The second part of the answer signals a major change in the EPO’s approach to assessing priority entitlement.  Under the autonomous law of the EPC, it is apparently now enough for the priority applicant to have consented to a priority claim in a subsequent application, there being no formal requirements laid down in this regard (“the EPO should … accept informal or tacit transfers of priority rights”), and the presumption being that consent was given.  The presumption of entitlement is rebuttable because “in rare exceptional cases the priority applicant may have legitimate reasons not to allow the subsequent applicant to rely on the priority.”  However, the rebuttable presumption is also “strong … under normal circumstances”, and thus a party challenging entitlement to priority “can … not just raise speculative doubts but must demonstrate that specific facts support doubts about the subsequent applicant’s entitlement to priority”.  

Support for the rebuttable presumption is said to be found “taking into account (i) that the priority applicant or its legal predecessor must under normal circumstances be presumed to accept the subsequent applicant’s reliance on the priority right, (ii) the lack of formal requirements for the transfer of priority rights and (iii) the necessary cooperation of the priority applicant with the subsequent applicant in order to allow the latter to rely on the priority right.”  A priority-claiming application is of course often filed before the priority application is published, thus implying a degree of cooperation between the priority applicant and subsequent applicant.

On the face of it, the new rebuttable presumption approach could put an end to many attacks on same-applicant priority in EPO opposition proceedings – an opponent may have to prove that the applicant for a subsequent application did not obtain consent from the priority applicant in order to claim priority, e.g. the subsequent applicant acted in bad faith.  Indeed, the Enlarged Board envisages that the approach “substantially limits the possibility of third parties, including opponents, to successfully challenge priority entitlement.”  

In further good news for applicants and patentees, the Enlarged Board also suggests that it should now be possible to fix those rare chain of title priority issues that do arise retroactively: “If there are jurisdictions that allow an ex post (‘nunc pro tunc’) transfer of priority rights …, the EPC should not apply higher standards.”

Second question

The second question, which applied if the Enlarged Board found that the EPO has jurisdiction to determine same-applicant priority, reads thus:

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?

The Enlarged Board answered the question as follows:

The rebuttable presumption also applies in situations where the European patent application derives from a PCT application and/or where the priority applicant(s) are not identical with the subsequent applicant(s).

In a situation where a PCT application is jointly filed by parties A and B, (i) designating party A for one or more designated States and party B for one or more other designated States, and (ii) claiming priority from an earlier patent application designating party A as the applicant, the joint filing implies an agreement between parties A and B allowing party B to rely on the priority, unless there are substantial factual indications to the contrary.

The answer is not surprising in view of the answer to the first question.  The threshold for disputing such an agreement between parties A and B is again high: “factual indications … of a substantial nature” are needed, e.g. evidence that “an agreement on the use of the priority right has not been reached or is fundamentally flawed”.


Many patents have been revoked by the EPO based on intervening art deemed relevant because priority entitlement was challenged and the patentee could not provide sufficient proof that the applicant for the European application (or international application designating Europe) was the successor in title to the priority applicant when the European application was filed.  It seems likely that in many of these cases, the priority claim would be deemed valid under the rebuttable presumption approach.  The Enlarged Board’s decision thus seems to mark a major relaxation of the EPO’s approach to same-applicant priority. 

Whether European national courts and the Unified Patent Court also now adopt the rebuttable presumption approach remains to be seen.  However, it seems unlikely that the Enlarged Board’s decision will be ignored in these other jurisdictions.