Many companies first register an invention nationally and then submit a European or international subsequent application within twelve months. Whether the priority is effective, can decide whether the patent survives or expires. With the decisions G 1/22 and G 2/22 from 10. October 2023 The Enlarged Board of Appeal of the EPO has ensured significantly more legal certainty here.

The problem

The priority may only claim, who was the applicant of the first application or is his legal successor. In PCT applications with multiple applicants for different states - typical for applications with US inventors - or in the absence of assignment agreements, opponents often attacked the priority.

The decision

• The EPO is responsible, to check the entitlement to claim priority.
• However, one applies rebuttable presumption, that the subsequent applicant is entitled to claim priority - even if he is not the same as the first applicant.
• Anyone who disputes eligibility, must serious doubts prove. A tacit agreement to transfer the priority right may be sufficient.

What does that mean for you??

Since then, priority attacks have significantly lost their effectiveness before the EPO. However, you shouldn't rely on it: National courts and the Unified Patent Court examine priority according to their own standards. Therefore, document transfers of inventions and priority rights in writing and in a timely manner - especially when Employee inventions and collaborations. More about Registration strategy.

Those: EPA, Große Beschwerdekammer, Decisions v. 10.10.2023, G 1/22 and G 2/22. General overview, no legal advice in individual cases. Stand: November 2026.