Contact Us

EPO's approach to double patenting is referred to Enlarged Board of Appeal

It is generally accepted that a patentee should not be entitled to protect the same invention twice (so called ‘double patenting’). However, there is nothing in the European Patent Convention (EPC) that allows the European Patent Office (EPO) to refuse an application on these grounds. 

The intention was that avoiding double patenting would be a matter for national law, but the approach of the national offices is not consistent. For example, the law in the UK makes no provision for conflict between two European patents from the same applicant that are both validated in the UK.

The EPO has, therefore, been keen to avoid any chance of double patenting centrally, in one particular instance resulting in a very forced (and widely criticised) interpretation of the language used in the EPC. Most recently, the EPO Boards of Appeal have accepted 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”.  

The guidelines suggest that this relies at least in part on Article 125 EPC, which states “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”.

In 2010, decision T 1423/07 assessed whether a European application could be refused for having identical scope to an earlier European application from which it claimed priority. It was held, in that case, that the later application could not be refused because there was “no principle of law generally recognised in the Contracting States for refusing a European patent application on the ground of double patenting”.  Only UK and Irish patent law contained specific provisions refusing a pending application based on apparent double patenting. Case law in Germany allowed for similar refusals on the basis that there was no ‘legitimate interest’ (seemingly forming the basis of the EPO approach).

The decision in T 1423/07 was seemingly distinguished from earlier decisions G1/05 and G1/06 based on the ‘legitimate interest’ point. It was suggested that the extra year of protection obtained from the later application (protection running 20 years from filing rather than from priority date) could be a ‘legitimate interest’ that was not under consideration in those earlier cases. Since there was said to be no conflict between the decisions, the matter was not referred to the Enlarged Board of Appeal (EBA), and there has been uncertainty as to generally how the EPO will now treat the question of double patenting, and what might constitute a ‘legitimate interest’.

Some of this uncertainty might now be resolved, following a referral to the EBA of the following 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?

The answer to Question 2.2 should provide the EPO’s definitive position on double patenting arising from priority forming and priority claiming applications (as in T 1423/07). Hopefully the other questions will also give a better indication of the EPO’s more general approach to double patenting in the future. We will await the outcome of the referral with interest.

Need some advice?

Call us on +44 (0) 115 947 7977 to speak to
one of our IP experts based in Nottingham, Leicester and London.

Providing professional services of the highest quality