EPO Decision Significantly Relaxes Patent Priority Approach

The European Patent Office's Enlarged Board of Appeal has issued a decision in the consolidated cases G 1/22 and G 2/22 on Oct. 10 that redefines the way that entitlement to priority is assessed at the EPO, significantly relaxing the previously strict approach.

This is a welcome development for many patent applicants and will make challenging the right to priority in post-grant opposition proceedings far more difficult.

However, applicants should still be mindful of the national law requirements in various contracting states of the European Patent Convention, or EPC, which may now be stricter than the EPO's more relaxed approach.

The Enlarged Board of Appeal's reasoning also leaves open questions as to the nature of the evidence that will be required to successfully challenge priority entitlement in disputes between co-owners of priority applications.