Tips for Drafting PCT Specifications – Episode 1, the EPO

The Patent Cooperation Treaty (PCT) offers many advantages. It delays the costs associated with foreign filings by up to 18 months. The international search report (and optional international preliminary examination process) offers applicants insight into at least some of the prior art an application may face during the national phase.

One of the shortcomings of the PCT is that only a single specification is filed, despite there being no such thing as a standard specification that’s ideal for all countries.  In this series, we’ll discuss elements that you should take into consideration when drafting PCT specifications in order to improve your chances of getting patent protection in various jurisdictions.  In this first episode, we’ll examine the European Patent Office’s (EPO) practices specifically.

Tweaking Disclosure for EPO Practice

The EPO has a number of practices that can trap the unwary patent draftsperson. Europe is also one of our most popular regional phase entry destinations. There are two aspects of EPO practice that reward a more open approach to drafting the specification than is typical in, say, the USA.

The first of these is the EPO’s approach to claim amendments. When considering whether to allow an amendment, the EPO adopts a stringent approach to new matter. If you want to take a feature from the specification and put it into the claims, you’ll need to show that the new claimed combination does not add new matter.

EPO Examiners are ruthless about this. Amendments should ideally have a firm linguistic basis in the description. If the verb/noun you want to introduce to a claim isn’t in the description, it’s likely you’ll face a fight getting the EPO to allow it into the claims. Strictly speaking, drawings can be used as the basis for amendments, but in practice it’s virtually impossible to convince some EPO Examiners that this is allowed.

On a related point, it’s common for the applicant to want to take a feature from one embodiment and use it to narrow an independent claim that is clearly directed to another embodiment. That might fly with the USPTO, but the EPO will likely refuse such an amendment unless the specific combination is expressly contemplated in the specification as filed.

Note that it’s not enough to show that the skilled person would have found it obvious to make the combination, or that the combination is trivial to implement – it must be clear that the specific combination is contemplated.

The second issue is the way inventive step is assessed in Europe. Before the USPTO, it’s often enough to show that a combination of features is novel, and that there is no teaching or motivation in the cited documents to combine the features in the manner claimed. The EPO usually requires more than that.

The EPO assesses inventive step using the “problem-solution approach”. In summary, the closest prior art is identified, an objective technical problem is constructed based on a difference between the closest prior art and the claim being assessed, then it is determined whether the skilled person would have found it obvious to modify the closest prior art in such a way as to arrive at the claimed invention, using the teachings of another document in the art or common general knowledge.

Some US attorneys provide instructions to their European associates showing how claim 1 is novel, concluding with something like “Since none of the citations show the novel feature, claim 1 is also inventive.” This may not be enough for the EPO. They may point out that the novel feature is mentioned only briefly in the description, and doesn’t appear to have any particular advantage associated with it. They therefore don’t consider it to be an invention, since it’s just an arbitrary novel feature.

The solution to this problem is to ensure that any feature you think might end up in a claim should be described not just in terms of technical details, but in terms of the advantages it offers.


Try to be consistent with language, and to provide as much information about each described feature as possible. If there’s any chance that a feature in the description might be imported into the claims, describe it in great detail, using the sort of language you’d want to use in a claim. Make sure that you explicitly state that features from one embodiment can be used with the other embodiments.


There are many subject matter specific areas that require specialist advice. For example, the EPO has a unique approach to software, biotech, medical diagnosis, and second-use type claims. If you have time and funds available, and intend to ultimately file in Europe, consider engaging a European patent attorney before filing the PCT (or even the priority document). They can provide specialist advice at the time when you have the most freedom to adjust the specification. Waiting until it’s time to enter the regional phase may well be leaving it too late.


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