This article explains how the EPO assesses amendments to European patent applications, focusing on the “Gold Standard” for added subject-matter, the need for clear original disclosure, and the risks of gaining an unwarranted advantage through unsupported changes
Amending a European patent application is a careful process governed by strict rules at the European Patent Office (EPO). Applicants are not allowed to add any new subject-matter that goes beyond what was originally disclosed in the application. This principle is enshrined in Article 123 EPC and is strictly enforced to ensure legal certainty for third parties.
The Gold Standard
The EPO applies a test known as the “Gold Standard” to assess whether an amendment adds impermissible new content. This standard requires that any amendments must be clearly and unambiguously derivable from the application as filed, from the point of view of a person skilled in the art, using their common general knowledge. The meaning of "skilled person" and "common general knowledge" can vary depending on the technology and circumstances, often introducing a layer of interpretation and complexity.
Sufficiency of disclosure
This is another key requirement. Any claim amendments must be rooted in the original application, with enough clarity and detail that a skilled person could carry out the invention. Features that lack support or are poorly cross-referenced in the original disclosure may be deemed insufficient, weakening the basis for any future amendment.
Unwarranted Advantages
The EPO also guards against applicants gaining unwarranted advantages. Even if an amendment narrows a claim, if it introduces a technical contribution not originally disclosed, it could unfairly extend the scope of the patent and compromise legal fairness. Specific examples of problematic amendments include unsubstantiated new ranges, disclaimers, and selections from broad lists of alternatives.
How to ensure compliance
To avoid problems, careful drafting at the application stage is essential, ensuring any future amendment is fully supported. With expert guidance, applicants can navigate these complex rules and keep amendments compliant with the EPO’s approach to added subject-matter.
For more information on this subject, click on the download button below.
