Patents
Posted on 2/3/2022

EPO Enlarged Board of Appeal referral relating to priority

The decision of the Enlarged Board of Appeal should provide clarification on a fundamental part of European patent law.

Background

For a valid priority claim at the European Patent Office (EPO), a European patent application must be filed by the applicant for the priority application or their successor in title.

A valid priority claim allows applicants to file a patent application but claim the filing date (priority date) of an earlier filed application.  If the requirements for a valid claim to priority are not met, the claim to priority may be lost and this may have considerable consequences on the validity of the later-filed patent application.

It has been the EPO’s practice for many years to acknowledge that a priority claim is valid if the applicant for the priority application, or their successor in title, is ‘amongst’ the applicants for the European patent application (EPC Guidelines for Examination, A-III, 6.1).

This means that provided an applicant for the priority application (i.e. a priority-entitled applicant) is named as an applicant for the European patent application, including additional applicants for the European patent application does not invalidate the claim to priority.  This is commonly referred to as a ‘joint applicants’ approach.

Recent interlocutory decisions of the Technical Board of Appeal (T 1513/17 and T 2719/19) have questioned the validity of a priority claim based on the joint applicants approach.   The interlocutory decisions discuss the case of a European patent application derived from a PCT (international) patent application, and question if a priority-entitled applicant is an applicant for the US only, and a different applicant, who is not priority-entitled, is the applicant for the European patent application, does the European patent application hold a valid claim to priority?

Before the introduction of the America Invents Act, this situation was commonly found in US-based inventions.  For example, a US provisional application is filed with an inventor as the applicant and a corresponding PCT application, which claims priority to the provisional application, is filed with the inventor listed as an applicant for the US only.  A second applicant, typically the inventor’s employer or other corporate entity, is named as the applicant for the remaining designated states (e.g. Europe).  In this case, and provided no transfer of priority right from the inventor to the second applicant has been made, the inventor is the only applicant who is priority-entitled but they are not an applicant for the remaining designated states.

One option may be for the inventor to transfer their priority right to the second applicant in order for the claim to priority to be valid in the remaining designated states.  However, with regard to a European patent application derived from the PCT application, and the above-mentioned EPC Guidelines for Examination, A-III, 6.1, the inventor would not be ‘amongst’ the joint applicants for such a European application.

Another option is that the PCT applicants for each designated state are to be considered as joint applicants because the PCT application is a single application having unitary character.  This approach is known as the ‘PCT joint applicants approach’ and considers each applicant of the designated states of the PCT application to be acting together.  In this case, no transfer of priority right from the inventor to the second applicant is required.

Recent decisions of EPO Opposition Divisions have followed the PCT joint applicants approach and do not require evidence to be provided of a transfer of priority right.  However, until now, this approach has not been referred to the Enlarged Board of Appeal.

The Appeal

In view of the above, two new questions relating to valid claims to priority have been referred to the Enlarged Board of Appeal (G1/22 and G2/22).

The first question asks whether the EPC confers jurisdiction on the EPO to determine whether a party validly claims to be a successor in title.  If a decision is made on this, the second question asks whether a claim to priority under the PCT joint applicants approach is valid.

The referral to the Enlarged Board of Appeal will consider a situation where:

  • An earlier (priority) application is filed with party A (e.g. an inventor) as the applicant; and
  • A PCT application is then filed, claiming priority of the earlier application, and designating party A as applicant for the US only and party B as applicant for other designated States, including Europe.

Conclusion

The decision of the Enlarged Board of Appeal should provide clarification on a fundamental part of European patent law.

It will be interesting to see whether the Enlarged Board of Appeal follows the recent practice of Opposition Divisions, or whether a different approach will be taken.

We will keep you updated with any further developments in this referral.  If you have any questions regarding this referral, please contact us to speak to one of our patent attorneys.