Article 123(2) of the European Patent Convention states that “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”. Whilst the patent law of most countries contains a similar provision, few patent offices are as strict in their application of it as the European Patent Office.

This is an issue we see crop up time and again for our clients, especially those filing from the US.

The standard applied by the EPO is that the amended claim must be directly and unambiguously derivable from the application as filed. Whilst support for an amendment may be implicit, in practice it is often difficult to persuade a European Examiner to accept any amendment not having literal basis in the application as filed.

The strict European approach to added matter can be frustrating for those used to the more relaxed approach of the USPTO, as often amendments which are readily permissible in the US run into problems at the EPO. For example in Europe it is generally extremely difficult to:

  • make intermediate generalisations, i.e. import a feature into a claim in isolation from an originally disclosed combination;
  • derive basis from examples or figures;
  • combine multiple features which are not specifically disclosed in combination; and
  • cross reference external documents

To further complicate matters, once a European patent is granted it is not possible to amend it in such a way as to extend the protection it confers (Article 123(3) EPC). The practical consequence of this is that if a limiting amendment introduced during prosecution is found, post-grant (e.g. in Opposition proceedings), to add matter in contravention of Article 123(2) EPC, it may not be possible to save the patent because deletion of the limiting feature would broaden the scope of the claim and thus violate Article 123(3).

This so-called Article 123(2)-123(3) “trap” means that it is especially important when drafting an application to include sufficient basis for potential amendments.

It is possible to minimise the likelihood of added matter objections arising in Europe by bearing in mind the following tips when drafting priority and PCT applications which might eventually end up before the European Patent Office:

  1. Include a claim matrix with multiple dependencies at the end of the description - this will ensure that you can later combine dependent claims from the original claim set;
  2. Ensure all the claim language is included in the description;
  3. Fallbacks should clearly refer back to claims of all categories - otherwise, it may be impossible to import a feature described in the context of a product into a method claim, or vice versa;
  4. Descriptions of preferred examples of claim features should link directly with the claim features, i.e. ensure consistent use of terminology throughout;
  5. Include tiered fallback positions;
  6. Include references to features both separately and in combination - this will help avoid accusations of intermediate generalisation