Requirements for claiming priority with the EPO, the same invention requirement

The right to claim priority from a previous application is an important aspect of patent law and was already recognized in the Paris Convention in 1883 (Art. 4 PC). For a European patent application there are several requirements that need to be fulfilled in order to validly claim priority, laid down in Art. 87 – 89 EPC. One of these requirements is the “same invention requirement” of Art. 87(1) EPC, which in short entails that the invention for which priority is claimed must be disclosed in the previous application.

When to consider the same invention requirement?

Any applicant wishing to file a European Patent application that claims priority from a previous application needs to exercise care in fulfilling the same invention requirement. The same care must be exercised regardless of whether the European Patent application is a direct filing claiming priority, or a Euro-PCT application entering the European phase from an international application claiming priority. In the latter case it may be advantageous if the claims of the international application already fulfil the same invention requirement.

What are the requirements for fulfilling the same invention requirement?

Priority of a previous application in respect of a claim is to be acknowledged only if the person skilled in the art can derive the subject-matter of the claim directly and unambiguously, using common general knowledge, from the previous application as a whole (see Enlarged Board of Appeal decision G2/98 hn.). This strict or narrow requirement corresponds to the requirement as set by Art. 123(2) EPC for an amendment not to introduce subject matter that goes beyond the application as filed. The subject matter for which priority is claimed must, in other words, be derivable from subject matter that is specifically disclosed, be it implicitly or explicitly, in the previous application as a whole (G2/98 r.2).

Is it a requirement that the subject matter for which priority is claimed must be found in the claims of the previous applications?

No, the subject matter for which priority is claimed may be derived from any part that constitutes the previous application, including the drawings (see Technical Board of Appeal decision T169/83). An exception is that the subject matter for which priority is claimed may not be found solely in that part of the description referring to prior art, or in an explicit disclaimer (GL F-VI,2.2).

What is meant by an implicit disclosure in the context of claiming priority?

An implicit disclosure of a feature in a previous application may be interpreted as any feature that is implicitly obvious to a person skilled in the art from what is explicitly disclosed. In the context of the same invention requirement of Art. 87(1) EPC, such an implicit disclosure will form part of what a skilled person can derive from the previous application as a whole. This means, in practical terms, that the subject-matter for which priority is claimed need not be explicitly reproducible word for word from the wording in the previous application (GL-F-VI.2.2).

Are there requirements on the disclosure in the previous application?

A claim may only enjoy a priority right from a previous application if the previous application comprises an enabling disclosure of the subject matter of the claim. This condition is a direct consequence of the fact that a disclosure in the meaning of G2/98 in the previous application may only be considered as effective if the skilled person can carry out the invention (T206/83 h.n.). The latter means that care should be exercised to ensure an enabling disclosure when drafting a first application, e.g. in the event where an application is drafted early in order to get a quick date of filing, or where an application is drafted based on an immature invention.

What happens if the same invention requirement is not fulfilled?

In the event where an applicant fails to fulfil the same invention requirement for a claim, he or she will lose the right of priority due to non-compliance with Art. 87(1) EPC. The previous application may therefore become prior art under Art. 54(2) EPC or Art. 54(3) EPC. Furthermore, other documents. Which are published after the date of filing of the previous application but before the date of filing of the new claim will become regular prior art under Art. 54(2) EPC.

If you would like further information or advice on the subject of claiming priority before the EPO, or just want to discuss the subject, please feel free to contact us at mail@baa.no.

Written by Fredrik Martinsen

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