Post-hearing update - EPO Enlarged Board of Appeal tackles entitlement to priority

Post-hearing update - EPO Enlarged Board of Appeal tackles entitlement to priority

A version of this article was previously published on WIPR.

We recently reported on the highly anticipated oral proceedings before the EPO Enlarged Board of Appeal on legal entitlement to priority (G 1/22 and G 2/22). Read on to find out what happened at the hearing and what it could mean for stakeholders.
To recap the EBA has been asked two questions, which can be summarised as follows:

  1. is the EPO competent to assess whether a party validly claims to be a successor in title? 

  2. is the priority claim for a European application valid where a priority application is filed by A and the priority claiming PCT application names A as an applicant for the US only but B as an applicant for all other states (including Europe)?

No decision was announced during the oral proceedings, which lasted less than three hours, but the positions of the parties after the hearing can be summarised as follows:

Party Proposed answer to question 1 Proposed answer to question 2
Appellant (patentee) Declined to comment directly in writing or at hearing Yes
Respondent 1 (opponent 1) No Yes
Respondent 2 (opponent 2) Yes Yes
EPO President Yes Yes
EBA preliminary opinion No indication given Yes (preliminary and non-binding)

We’ll have to wait for the written decision to find out the EBA’s answers to these questions, but in the meantime we discuss below some interesting points from the hearing and possible implications of the EBA’s decision.


What happened at the hearing?

Question 1
Opponent 1 was the only party arguing that the EPO should not assess whether a party validly claims to be a successor in title. Reasons for this included:

  • There has been no transfer of sovereign rights to the EPO to decide on this aspect of property law.

  • Legislators consider the assessment of the transfer of priority rights by the EPO as untoward interference in national law and that the EPO should be relieved of this burden.

If the EBA were to conclude the answer to Q1 is “yes”, Opponent 1 suggested that the EPC should be the relevant law and the power of the EPO to determine if the applicant is the successor in title should be restricted to situations where there is substantiated doubt. The EPO should also not apply any particular formal requirements when assessing transfer of priority rights.
Opponent 2’s position is that the EPO should assess entitlement to priority where this is relevant, for example to determine what is prior art. Arguments included:

  • The case law has always supported the EPO's competence to assess entitlement to priority. The increase in objections based on the entitlement to priority is not due to a change in practice at the EPO, but due to external factors such as globalisation and increase in knowledge leading to more patent applications and prior art, and the introduction of provisional applications in the US.

  • Entitlement to the patent itself doesn’t affect patentability, whereas the entitlement to priority can. It is therefore necessary to assess the entitlement to priority in order to grant a patent.

  • The applicant for the priority application should be deemed entitled to the priority application, for consistency with the EPO’s approach that the applicant is deemed to be entitled to the application. 

The representatives of the President of the EPO also made submissions to the EBA, focussing on the practical impact of the decision and noted it is the current and historical practice of the EPO to examine priority entitlement when required. It was emphasised that formal validity of priority potentially impacts the scope of prior art for assessing patentability. The competence to assess the validity of the formal priority claim is hence very closely linked to the competence to determine the scope of prior art reliably – which is indispensable to guarantee the quality of European patents and provide legal certainty.
Question 2
All parties (and the representative of the President) agreed with the preliminary opinion of the EBA that the answer to Q2 should be “yes”. General support was given for a PCT application being a single application and the PCT joint applicants approach therefore being correct. All parties agreed that joint filing of a PCT implies agreement between all applicants, and is therefore evidence for an informal or implied agreement regarding the sharing or transfer of the priority right.


It seems unlikely the EBA will upset the apple cart by ruling the EPO is not competent to perform a task it has ostensibly done for many years – particularly as this could render many previous decisions incorrect, and even impact the EPO’s ability to grant quality patents if the scope of the prior art cannot be assessed.
If the EBA does answer “yes” to Question 1, it will be interesting to see how extensively they look at the requirements for a valid transfer of the priority right. There is an opportunity to provide some much-needed clarity on an issue that is relevant in a large number of European cases. However, the EBA may find a way to confine itself to focusing specifically on the issue in Question 2 without going into the broader questions around the requirements for a valid transfer of the priority right.
It seems a reasonably safe bet that Question 2 will be answered in the affirmative (assuming the answer to Question 1 is also yes). This would clearly be good news for applicants and patentees whose applications or granted patents fall within the Question 2 scenario. On the other hand, such a decision could work in favour of opponents relying on a valid priority date for a piece of prior art, where the prior art is a European application falling under the Question 2 scenario. All interested parties will hope the decision is clear on whether any evidence of a transfer beyond the filing of the PCT itself is required, and likewise what evidence might show that the priority claim is not valid even if, on the face of it, the Question 2 scenario applies.
We look forward to the decision of the EBA and will keep you updated

Get in touch

If you have questions about a priority claim or a more general query on priority at the EPO, please contact Abi HeathJamie Atkins or your usual Kilburn & Strode advisor.

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