Opposition proceedings provide an effective legal mechanism for third parties to challenge the validity of a granted European or national patent. For both European and Norwegian patents, an opposition may be filed within nine months of the publication of the patent grant, often with decisive impact on the patent’s commercial value.

A successful opposition may result in the patent being revoked in whole or in part, for example where the requirements for patentability are not met, such as lack of novelty or inventive step, insufficient disclosure, or where the claims extend beyond the content of the original application. Conversely, a well‑prepared defense in opposition proceedings is often critical to preserving and strengthening valuable patent rights.

Experienced Representation Before the EPO

At Acapo‑Onsagers, our European Patent Attorneys have extensive experience representing clients in opposition proceedings before the European Patent Office (EPO).

We act for both patentees and opponents, providing comprehensive support throughout all stages of opposition and appeal proceedings, including matters before the Boards of Appeal.

Our advisors combine in‑depth legal expertise with strong technical knowledge across a broad range of industries, ensuring clear, persuasive arguments grounded in both law and technology

Balanced Representation for Patentees and Opponents

Opposition proceedings serve different but equally important strategic purposes. While robust defense is essential for patentees seeking to safeguard and strengthen granted rights, opposition is also a vital tool for companies whose commercial freedom is constrained by third party patents that may have been improperly granted or are overly broad.

Acting for both patentees and opponents gives us a deep understanding of the procedural dynamics and strategic considerations on both sides, insight that consistently strengthens the quality and effectiveness of our representation.

End‑to‑End Support - From Strategy to Oral Hearings

We assist clients with:

Strategic assessments prior to filing an opposition or defense
Preparation, filing and management of oppositions and responses
Representation in oral proceedings before the Opposition Divisions and Boards of Appeal
Appeal strategy and proceedings

Our approach is always commercially focused, helping clients make informed decisions that align legal actions with business objectives.

Optimised Facilities for Oral Proceedings

In response to the EPO’s practice of conducting oral proceedings in opposition cases primarily by videoconference, we have established a dedicated hearing room specifically designed for EPO opposition and appeal proceedings. This ensures optimal technical and professional conditions, facilitates efficient preparation, and provides a convenient and effective solution for client participation.

National and International Reach

In addition to EPO matters, we have long‑standing experience handling opposition proceedings before the Norwegian Industrial Property Office. Through our established international network of trusted patent agents, we also coordinate and manage opposition matters in other key jurisdictions worldwide, offering seamless cross‑border support.

Tailored Strategies for Maximum Impact

By working closely with our clients, we develop tailored opposition strategies designed to:

secure strong and enforceable patent rights, or
effectively challenge third‑party patents of commercial relevance

Our goal is to deliver clear, strategic advice and robust representation, helping our clients protect their innovations and maintain a strong competitive position.