Priority in Euro - PCT : EPO G 1/22 and G 2/22

Priority rights and the validity of a claimed priority are a recurring topic of dispute before the European Patent Office.

In decisions G 1/22 and G 2/22, the Enlarged Board of Appeal of the EPO recently provided clarity relating to priority rights, particularly in connection with a Euro - PCT application - and with findings in favour of applicants and patent proprietors.

The facts

Decisions G 1/22 and G 2/22 are answers of the Enlarged Board of Appeal of the EPO to questions referred by the Technical Board of Appeal 3.3.04 from the two appeal cases T 1513/17 and T 2719/19.

The following questions were referred:

Does the EPC confer jurisdiction on the EPO to decide whether a party rightly claims to be a successor in title within the meaning of Article 87(1)(b) EPC?

And if the answer is yes, what applies to the Euro - PCT application if the applicant(s) of the priority application and the Euro - PCT patent application are not identical?

In the two appeal cases, both the Opposition Division and the Examining Division declared the priority claim invalid because not all inventors named as applicants in the US priority patent application had assigned the priority right to the applicants of the respective Euro - PCT applications.

Thus, if patent applicant A filed the priority application in the USA, but party B invokes the claimed priority right for the Euro - PCT application in order to claim the priority right under Article 87(1) EPC: Can party B validly claim priority?

Priority Decisions G 1/22 and G 2/22 of the Enlarged Board of Appeal

The Enlarged Board of Appeal answered the first question referred in the affirmative and thus established that the EPO can decide on the validity of a transfer of priority rights to be examined by the EPO. This also applies in the context of the EPO deciding whether a priority right is validly and rightly claimed in a Euro - PCT application.

And the national courts? The fact is that national courts apply different standards in relation to the assignment of priority rights. Can the EPO impose higher standards than the national laws?

Accordingly, the Enlarged Board of Appeal in G 1/22 and G 2/22 decided that the EPO should not apply higher standards, especially since there is national case law allowing even for a subsequent ("nunc pro tunc") transfer of priority rights (see G 1/22 and G 2/22 paragraph 100).

This opens the door wide for effective transfers of priority rights before the EPO, clearly in favour of patent applicants and patent proprietors.

Implied transfer assignment of the priority right

In praxis, this raises the question of the formal requirements for an effective priority claim. And in this respect, decisions G 1/22 and G 2/22 seem to favour the allowance of informal claims to priority.

In particular, G 1/22 and G 2/22 state in paragraph 100 that the autonomous law of the EPC should not require the transfer of priority rights to be in writing and/or signed by the parties. Thus, if different applicants agree on the priority right, a submission that the priority right has been transferred orally could be perfectly sufficient for a valid priority claim if the applicant(s) of the priority application and the European patent application are not identical.

The Enlarged Board of Appeal thus confirms the approach of an implied agreement. According to the Enlarged Board of Appel the concept for an implied agreement applies both to a later filed Euro - PCT application and to co-applicants directly filing a subsequent European application - if at least one of the co-applicants was an applicant for the priority application (see G 1/22 and G 2/22 paragraph 125).

Reversal of the burden of proof for priority claims

The decisions G 1/22 and G 2/22 go even further. According to G1/22 and G 2/22, an applicant claiming priority can now rely on a "rebuttable presumption" under the EPC that he is entitled to claim such priority.
In practice, this means that the priority claim is always considered valid as soon as it is asserted - until proven otherwise. And this proof that a priority was inadmissably claimed must be provided by the opponent, i.e. "the party challenging the priority claim of the later applicant" (paragraph 110 of decision G1/22 and G 2/22).
This is a significant turnaround from the previous case law, where the patentee bore the burden of proving that the priority claim was valid when challenged.

And together with the concept of an "implied agreement" hinted at above, the practical question arises:
How should an opponent(s) ever be able to prove that there was no lawful transfer of priority rights before filing a European patent application if such a transfer is recognised even without any correspondence? Even if no written assignment can be found, an oral or an implied agreement could have been made or assumed at any time.

It remains to be seen what effect this will have in practice in future national decisions, some of which will impose stricter requirements for proving the right of priority.
The following recent decision by the German Federal Supreme Court (BGH) is therefore interesting.

BGH welcomes decision G1/22 and G 2/22

The Federal Supreme Court (BGH) already took a position on the EPO decisions G 1/22 and G 2/22 at the end of November 2023 (BGH, X ZR 83/21). The BGH welcomes the decisions and described them as "carefully and convincingly reasoned". In addition, the court said that the findings of the Enlarged Board of Appeal lead to "realistic and interest-orientated results".

Although not all applicants had contracts for a transfer of priority and although one of the assignment agreements could be invalid under German law, the BGH did not regard this as proof that the defendant applicant had no right to the claimed priority. This is because oral agreements could have been made.
You'll find the whole BGH decision in our blog post on Priority right: BGH consents to EPO G 1/22 and G2/22.

It is still advisable to transfer or obtain the priority right in writing before filing a patent application claiming priority. This is because other national courts may decide differently and national courts are not bound by decisions of the EPO.

Patent applicants and patent proprietors with problems claiming priority should carefully review their circumstances. We will be happy to support you.

Please do not hesitate to contact us. You can reach us by phone +49 69 69 59 60-0 or please send us an email info@kollner.eu.