Article 123(2) of the European Patent Convention reads as follows:

“The European patent application or patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed”.

A short sentence causing a headache to many – Why!

Although the patent laws of other countries contain similar patentability requirements, few patent offices are as strict in applying this as the EPO. According to the EPO, any amendments to the claims must be directly and unambiguously derivable from the application as originally filed. The term “directly and unambiguously derivable” finds no basis in the EPC and was developed instead through EPO case law. Thus, whilst support for an amendment may be implicit, in practice it is often difficult to persuade an EPO Examiner that any amendment not having literal basis in the originally filed application may be allowed. The different EPO Boards have infrequently applied the “novelty test” (T201/83) in recent cases, but this test was referred to in e.g. T 60/03, T 1374/07, T 2202/08, T 2270/09. Specifically, according to T 2537/10, the novelty test is no longer applicable for the assessment of added matter under Art. 123(2) EPC. Although, reference was still made to this test in the 2015 version of the Guidelines (H‑IV, 2.2), in particular when the amendment is by way of addition to the claims.

For instance, compared to USPTO patent prosecution practice where amendments to claims may be readily allowable, these however, much to the annoyance of US clients, often run into serious difficulties at the EPO!

Why is this?

Well, here is an illustration of some situations at the EPO, where it is difficult to amend claims:

• rely on external expert witness declarations for basis;
• importing a feature in isolation from an original combination – intermediate generalisation;
• rely on basis from examples or figures;
• combine multiple features from different lists which are not specifically disclosed in combination; and
• cross reference external documents.

Please note that if after EP patent, an amendment introduced during prosecution is found, post-grant to add matter in contravention of Art 123(2), it may not be possible to save the patent because removal of the limiting feature would broaden the scope of the claim and thus violate Art 123(3) EPC.

Art 123(2)-123(3) EPC “inescapable trap” considerations are critical when originally drafting an application. It is possible to minimise the likelihood of added matter issues in EPO by bearing mindful of the following when drafting applications which may end up before EPO Examiners:

• Include a claims table with multiple dependencies and cross reference
• Add a table individualising all possible combinations of features from different lists of features
• Ensure all the claim language with alternatives is included in the application as filed
• Fall-back positions should clearly refer back to claims of all categories
• Descriptions of preferred examples of claimed features should link directly with the claim features
• Include tiered fall-back positions in order of envisaged relevance the claimed invention
• Enter national phase (EP-PCT) with the text (description, claims figures) of the original application
• Include references to features both separately and in combination.