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15.07.21

Double Patenting – Decision of the Enlarged Board of Appeal (G4/19)

The Enlarged Board of Appeal has confirmed that a European patent application can be refused for double patenting.

Background

Under normal circumstances it is not possible to obtain two patents for the same invention because the earlier patent for the invention will act as prior art against the later one, causing the claims of the later patent to lack novelty. However, double patenting can still arise when a single applicant attempts to protect the same invention in two European patent applications having the same effective filing date.

More specifically, the following three types of European applications by the same applicant can lead to double patenting if they claim the same invention:

  1. two applications filed on the same day,
  2. parent and divisional applications, and
  3. an application and its priority application (so called “internal priority”, meaning both applications are European patent applications).

There is no provision in the European Patent Convention prohibiting double patenting. However, in practice the EPO takes the view that double patenting is not permissible. The EPO’s Guidelines for Examination state that: “… in the rare case in which there are two or more European applications from the same applicant … and the claims of those applications … relate to the same invention, the applicant should be told that he must either amend one or more of the applications in such a manner that the subject-matter of the claims of the applications is not identical, or choose which one of those applications he wishes to proceed to grant.” The legal basis for this practice is embedded in the notion that “an applicant has no legitimate interest in proceedings leading to the grant of a second patent for the same subject-matter if the applicant already possesses one granted patent for that subject-matter” (G1/05 and G1/06).

Technical Board of Appeal Case

In a recent case before the Technical Board of Appeal (T 318/14, OJ EPO 2020, A104), the legal basis for refusing an application for double patenting was called into question. The European patent application (EP2429542) under consideration claimed subject-matter identical to that of an earlier (granted) European patent (EP2251021) from which it claimed priority. The examining division had previously rejected the patent application on the basis that it claimed “100% identical” subject-matter to the earlier patent.

The appellant appealed against this decision and argued that the above-established principle of prohibition (G1/05 and G1/06) did not apply because there was a legitimate interest in the grant of a second patent for identical subject-matter, namely an additional year of protection for their invention. The additional year of protection results from the fact that the duration of a patent is calculated from its filing date rather than its priority date. This means that a later patent claiming priority from an earlier patent expires later than the earlier patent by an amount equal to the difference in their filing dates, which can be up to a year.

Referral to the Enlarged Board of Appeal

The Board of Appeal in the above case sought to clarify whether a legal basis existed for the EPO’s practice on refusing an application for double patenting. If such basis existed, the Board also wanted to establish what conditions could give rise to a double patenting objection. For those reasons, the Board of Appeal asked the Enlarged Board of Appeal to consider the following series of questions.

Questions:

1. Can a European patent application be refused under Article 97(2) EPC if it claims the same subject-matter as a European patent granted to the same applicant which does not form part of the state of the art pursuant to Article 54(2) and (3) EPC?

2.1  If the answer to the first question is yes, what are the conditions for such a refusal and are different conditions to be applied where 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?

2.2 In particular, in the latter case, does an applicant have a legitimate interest in the grant of 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?

Decision of the Enlarged Board of Appeal

The Enlarged Board of Appeal came to the following conclusions on the above questions in decision G4/19, which was issued on 22 June 2021.

1. 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.

2.1 The application can be refused on that legal basis, 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.

2.2 In view of the answer to Question 2.1 a separate answer is not required.

Conclusion

The Enlarged Board of Appeal confirmed that, despite the absence of an explicit anti-double patenting provision in the European Patent Convention, a patent application can be refused for double patenting. Notably, the double patenting prohibition not only applies to two separate patent applications filed by the same applicant on the same day, but also applies to divisional and parent applications and to an application claiming priority from an earlier European patent application.

The Enlarged Board of Appeal further confirmed that 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. We note that in this situation it would be possible to avoid the problem by abandoning the earlier priority patent at an appropriate time, so that only one patent for the invention exists and the invention remains protected until the end of the duration of the later patent.

If you have any questions on this topic, please contact Andy Cloughley at andycloughley@mskpatents.com.

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