Enlarged Board of Appeal rules on double patenting

On June 22 2021, the Enlarged Board of Appeal of the European Patent Office issued decision G 4/19 (Double patenting), in which it held that a European patent (EP) application can be refused if it claims the same subject matter as a granted European patent (i.e. not just a co-pending EP application) which has been granted to the same applicant and has the same effective date. 

The application can be refused irrespective of whether it (a) was filed on the same date as, or (b) is a parent application or a divisional application of, or (c) claims the same priority as the European patent already granted.

In other words: if an applicant already achieved grant of an EP patent on a certain subject matter, the Examining Division will deny grant to claims on the ‘same’ subject matter in later examination proceedings pertaining to an application having the same ‘effective date’ as the granted patent.

This even applies if the EP patent that was granted earlier is the priority application of the later-examined application. The advantage of a longer term of protection (due to the later filing date) that is thus lost for the applicant is no justification for allowing double patenting.

The Enlarged Board of Appeal relied on Article 125 EPC, which stipulates that “in the absence of procedural provisions in this Convention, the European Patent Office shall take into account the principles of procedural law generally recognised in the Contracting States”.

Two pieces of the puzzle, however, were deliberately not examined by the Enlarged Board of Appeal. First, even though the referring Board asked for clarification, the concept of ‘same subject matter’ was not addressed (does overlap also count?). Second, the question whether the rules on double patenting will also have to be applied in opposition proceedings remained unanswered.

But we notice that a distinction between ‘double protection’ (claims with overlapping scope) and ‘double patenting’ was made in the Reasons, and we are therefore quite confident that the prohibition of double patenting will remain a prohibition of double patenting in a narrow sense, limited to claims on exactly the ‘same’ invention. Overlapping claims should, therefore, remain admissible.

Thus, tailoring the claims of the later application to a merely overlapping claim scope might still provide the possibility to get the later application granted. It remains to be seen whether filing a request for revocation of the earlier patent will be allowed as a means to address a double patenting situation. 

We are also curious to see whether double patenting rules will now be applied more often in opposition proceedings; at present, applying them is within the discretion of an opposition division. 

Annelie Wünsche

Partner, Maiwald 

E: wuensche@maiwald.eu

Stefanie Parchmann

Partner, Maiwald 

E: parchmann@maiwald.eu