Home > Insights > Double Patenting – Decision of the Enlarged Board of Appeal in G4/19
5 July, 2021

With no provision in the European Patent Convention (EPC) prohibiting double patenting, is the European Patent Office (EPO) nevertheless allowed to refuse to grant a patent application on that ground? The Enlarged Board of Appeal of the EPO (EBA) has recently answered this question in decision G4/19, taking a harder line than expected.

Background
Double patenting is the granting of more than one patent to the same applicant for the same invention within the same jurisdiction, and is prohibited under a number of patent systems around the world.

At the EPO, however, the EPC itself does not specifically discuss double patenting. Despite this, it has become established practice at the EPO that two European applications may not be granted if they a) are considered to have been filed on the same date, whether as separate applications or one as a divisional of the other, b) are filed by the same applicant, and c) claim the same subject-matter, the prohibition being based on the double patenting principle. Indeed, a number of earlier decisions of the EBA, namely G1/05 and G1/06, established that, “the principle of prohibition of double patenting exists on the basis that an applicant has no legitimate interest in proceedings leading to the grant of a second patent for the same subject-matter if he already possesses one granted patent therefor”.

Referral
However, in a recent case before the Technical Board of Appeal (T318/14), both the legal basis in the EPC for refusing an application for double patenting, and the conditions for any such refusal, were called into question. In particular, the application under consideration claimed subject-matter identical to that of an earlier, directly filed, European application from which it claimed priority. The appellant argued that the principle of prohibition of double patenting established in G1/05 and G1/06 did not apply to the situation at hand, where a European application claimed the same subject-matter as an earlier filed European application from which it claimed priority (so called ‘internal priority’), since there was a legitimate interest in the grant of a second patent for the same subject-matter. In particular, because the filing date, and not the priority date, is used to calculate the 20-year term of a patent, a second patent for the same subject-matter as an application from which it claimed internal priority could provide an applicant up to a year of additional protection for their invention. The Board of Appeal therefore sought to clarify the EPO’s legal position on, and legal basis for, the prohibition of double patenting by asking the EBA to consider a number of questions.

Referred Questions
The first question referred to the EBA essentially asked the EBA to confirm that an application could be refused under the EPC on the basis of double patenting and what the legal basis for doing so was. The question asked was, “Can a European patent application be refused under Article 97(2) EPC if it claims the same subject-matter as a European patent which was granted to the same applicant and does not form part of the state of the art pursuant to Article 54(2) and (3) EPC?”

Secondly, arguably the most important question referred to the EBA, and the crux of the matter at hand, was whether there are “different conditions to be applied depending on whether the European patent application under examination was filed a) on the same date as, or b) as a European divisional application (Article 76(1) EPC) in respect of, or c) claiming the priority (Article 88 EPC) in respect of, a European patent application on the basis of which a European patent was granted to the same applicant?”

Finally, there was a second part to this question which asked the EBA to consider the appellant’s arguments regarding there being a legitimate interest in obtaining a second patent for the same subject-matter as an application from which it claimed internal priority, for the extended term of protection: “in the last of these cases, does an applicant have a legitimate interest in the grant of a patent on the (subsequent) European patent application in view of the fact that the filing date and not the priority date is the relevant date for calculating the term of the European patent under Article 63(1) EPC?”

Answers
In answer to the first question, the EBA stated that, “A European patent application can be refused under Articles 97(2) and 125 EPC if it claims the same subject-matter as a European patent which has been granted to the same applicant and does not form part of the state of the art pursuant to Article 54(2) and (3) EPC”. That is, the EBA confirmed the previous position that there is a prohibition on double patenting at the EPO, and that the legal basis for doing so may be found in Article 125 EPC. Article 125 EPC states 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”. The EBA consulted the travaux préparatoires of the EPC which, when discussing the implications of Article 125 EPC, noted that, “it was a generally recognised principle of procedural law in the Contracting States that a person can be granted only one European patent for the same invention in respect of which there are several applications with the same date of filing”. The EBA held that the “same date of filing” had to be understood to be the “effective date” of the application, such that applications having different filing dates but the same priority date were also covered.

Following from this, and in answer to the second question, the EBA stated that that an application can be refused for double patenting “irrespective of whether it a) was filed on the same date as, or b) is an earlier application or a divisional application (Article 76(1) EPC) in respect of, or c) claims the same priority (Article 88 EPC) as, the European patent application leading to the European patent already granted”, with the board then stating that there was no need to provide a separate answer to the final part of this question.

It is worth noting that the EBA decision relates only to double patenting in a narrow sense, as between two European patent applications, and not between either a) a national patent application in an EPO member state and a European patent application (simultaneous protection by a national and a European patent), or b) two European patent applications where the scope of the claims overlaps but is not fully the same (so-called ‘double protection’). Thus the double patenting prohibition only applies where the claim scope is the same between two European cases, and then only for commonly designated EPO member states.

Conclusion
In summary, the Enlarged Board of Appeal held that there is a prohibition on double patenting at the EPO; namely, against the granting of more than one patent to the same applicant for the same invention for commonly designated EPO states. The prohibition is not limited only to applications which were filed on the same day, but also to applications having the same priority date. As such, at the EPO, the possibility of an additional year of protection using internal priority is not considered to provide a legitimate interest in obtaining a second European patent for the same invention. In other words, the prohibition of double patenting applies to three types of combinations of European applications by the same applicant: a) two applications filed on the same day, b) parent and divisional applications, and c) an application and its priority application.