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Commercially focussed strategies to help you navigate disputes at every stage

What do we mean by oppositions at the EPO?

An opposition is a means of challenging the validity of a European patent after grant. An EPO opposition is a centralised invalidity procedure, which is available for a finite period following grant. Unlike action before the Unified Patent Court (UPC) or in national Courts, a successful opposition can revoke or limit the patent across all 39 member states, securing freedom to operate across Europe. An opposition can be filed at any time within 9 months following the mention of grant of the patent in the European Patent Bulletin. Statistically, oppositions are very effective at limiting the protection of opposed patents – less than a third of opposed patents are maintained as granted.

Exceptional track record in EPO patent oppositions

No other IP firm has our depth of expertise over such a wide range of technologies 

Marks & Clerk have an enviable track record for both offensive and defensive oppositions. With opposition specialists across all technology sectors and a proven approach, it is unsurprising that technology companies trust their opposition practice to us. Our specialists have a wealth of experience of managing the unique EPO opposition and appeal procedure. We understand that commercial objectives for oppositions are as varied as the technologies and our approach focuses on achieving success based on our clients’ metrics. Our opposition specialists are particularly valued either leading or working with a wider contentious team – oppositions and appeals often form part of a wider strategy and our team has particular expertise in managing the EPO proceedings to achieve maximum benefit for the wider strategy. 

Choosing the best firm for your needs

"After taking over a complex European Patent Office (EPO) appeal following an initial opposition loss, the team at Marks & Clerk successfully managed to reverse the outcome, leading to a significant victory and the revocation of a competitor's patent.
 
Daniel Sizer and Thomas Prock quickly integrated with our broader litigation team and effectively focused the EPO case on the strongest arguments while maintaining alignment with our wider litigation strategy. They expertly managed the written procedure and streamlined the case to its key issues, demonstrating a strong grasp of the Board's approach. They clearly understood the nuances of the EPO appeal process and steered the case with skill. They were equally impressive during the oral hearing, managing the process effectively and reacting to developments assuredly. Additionally, Daniel and Thomas provided valuable input to our wider multinational litigation, demonstrating a clear understanding of our commercial goals and adding significant value." – Evan Feldstein, General Manager and General Counsel, FOREO
Thomas Prock is a Partner, German, European and Chartered (UK) Patent Attorney, UPC Representative based in Marks & Clerk's London, UK office. Thomas advises clients in the high-tech field, in particular, in the electronics sector on software, artificial intelligence and internet related subject matter.

Thomas Prock

Partner German, European and Chartered (UK) Patent Attorney, UPC Representative
Thomas advises clients in the high-tech field, in particular, in the electronics sector on software, artificial intelligence and internet related subject matter. He has extensive experience working with the European Patent Office (EPO) and advising clients on patent strategies across participating member states.
Will Nieuwenhuys is a Partner, Chartered (UK) and European Patent Attorney, UPC Representative based in Marks & Clerk's London, UK office. Will has experience in a variety of technical fields, with particular expertise in small molecule organic and pharmaceutical chemistry.

Will Nieuwenhuys

Partner Chartered (UK) and European Patent Attorney, UPC Representative
Will has experience in a variety of technical fields, with particular expertise in small molecule organic and pharmaceutical chemistry. His work often involves representing clients before the European Patent Office (EPO) and advising on patent strategies across participating member states.
Kirsteen Gordon is a Chartered (UK) and European Patent Attorney, UPC Representative based in Marks & Clerk's Cambridge, UK office.

Kirsteen Gordon

Partner Chartered (UK) and European Patent Attorney, UPC Representative
Kirsteen drafts, files and prosecutes patent applications worldwide and has experience of opposition and appeal work at the European Patent Office.
Andrew Docherty is a Partner, Chartered (UK) and European Patent Attorney, UPC Representative based in Marks & Clerk's Aberdeen, UK office.

Andrew Docherty

Partner Chartered (UK) and European Patent Attorney, UPC Representative
Andrew specialises in the field of engineering, with extensive experience in technologies relating to the oil and gas industry, advising a myriad of clients across multiple jurisdictions on all aspects of IP, from protection through to enforcement and strategic management of third party IP risks.
Daniel Sizer is a Partner, Chartered (UK) and European Patent Attorney, UPC Representative based in Marks & Clerk's London, UK office. He has a broad background in Mechanical Engineering.

Daniel Sizer

Partner Chartered (UK) and European Patent Attorney, UPC Representative
Daniel is a Chartered (UK) and European Patent Attorney whose broad background in Mechanical Engineering allows him to work across a range of technologies spanning the energy, automotive, consumer device and medical technologies.
Daniel McGrath is a Partner and Solicitor (UK) for Marks & Clerk based in London, UK

Daniel McGrath

Partner Solicitor (UK)
Dan is a Partner and a leading patent litigator, specialising in life sciences and biopharmaceutical disputes. He has extensive experience in high-stakes patent and Supplementary Protection Certificate (SPC) litigation before the English courts and the Unified Patent Court (UPC).
Photo: David Lang

David Lang

Principal Chartered (UK) and European Patent Attorney, UPC Representative
David’s patent practice covers a broad variety of technical fields, with particular emphasis on chemistry and pharmaceuticals.

Elliot Carrington

Associate Chartered (UK) and European Patent Attorney
Elliot handles patent matters in the materials science and chemistry sectors, with an emphasis on green and renewable technologies, polymeric materials, industrial chemistry, and medical and diagnostic devices.

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