Observations by third parties in patent proceedings before the GPTO and EPO

May 2, 2025

Observations by third parties are an important tool in patent proceedings, allowing external parties to contribute relevant information to a pending patent application. It makes it possible to influence the examination of patent applications without becoming a party to the proceedings. Both before the German Patent and Trade Mark Office (GPTO) and the European Patent Office (EPO), there are clear rules on observations by third parties, although they differ in some respects.

Observations by third parties before the GPTO

Before the GPTO third parties observation are regulated in §43 of the German patent law. Third parties can provide the Office with written information on the patentability of the invention, for example by submitting relevant prior art documents. These submissions can be made anonymously and are possible at any time during the examination procedure. The Examining Section of the GPTO takes this information into account in its decision, but the third party itself is not involved in the procedure.

Observations by third parties before the EPO

At the EPO, observations by third parties are governed by Article 115 of the European Patent Convention . Here, observations can be submitted in writing in one of the official languages of the EPO, i.e. German, English or French. Anonymous filing is also possible at the EPO. A major difference to the GPTO is that the submissions are made publicly accessible and included in the case file.

Benefit of filing observations by third parties

The main benefit of observations by third parties is the prevention of patents being granted that do not meet the legal requirements. By submitting relevant documents, it is possible to prevent unauthorized or non-inventive patents from being granted. Observations by third parties is also a cost-effective alternative to opposition or nullity proceedings, as it is free of charge and only incurs internal costs for searching and preparing the documents to be submitted. Another advantage is the early influence on the examination procedure before a patent is granted.

Risks of filing observations by third parties

However, there are also risks. The third party is not acknowledged as a party to the proceedings and is therefore not entitled to feedback or notification of the outcome of the proceedings. In addition, the applicant can be sensitized, which can lead to the applicant strengthening his IP strategy. Even if the application is made anonymously, it may be possible to draw conclusions about the third party if specific specialist knowledge is available.

Differences between the GPTO and the EPO

The main differences between the GPTO and the EPO are the public accessibility of the submissions and the language requirements. While documents submitted to the GPTO are not publicly accessible, they are included in the file at the EPO and can be inspected by third parties. In addition, submissions to the EPO can be made in German, English or French, whereas German is mandatory at the GPTO .

Conclusion

Overall, fling observations an effective and inexpensive means of influencing patent proceedings and preventing unauthorized property rights. The strategic use of this instrument can help to secure a competitive position and avoid legal disputes at later stages of the proceedings.