Opposing and defending a patent at the EPO

In the nine months following the grant of a European patent by the European Patent Office, the patent is open to opposition by third parties. This gives you a chance to challenge the patent of a competitor if you consider that it may restrict your commercial activities. Alternatively, you may have to defend your own patent from an opposition filed by a third party.

The opposition procedure involves a written stage, during which the opponent sets out why they consider the patent should not have been granted. The patentee will then have an opportunity to respond.


Opposition proceedings usually culminate in oral proceedings before the Opposition Division at the EPO’s offices in Munich, The Hague or Berlin.


Once the patent proprietor and the opponents have had an opportunity to present their arguments for and against the patent, the EPO Opposition Division will decide to:

  • maintain the patent as granted;
  • maintain the patent in amended form; or
  • revoke the patent in its entirety.


If oral proceedings are held, the decision will usually be indicated at the end of the oral proceedings, and a written decision will be issued thereafter. The written decision will set out the Division’s reasoning. Decisions from the Opposition Divisions can be appealed to the EPO Boards of Appeal.


How we can assist you in opposing a patent

Successful representation in opposition proceedings requires highly-specialised skills and experience. Page White Farrer has been involved in countless opposition proceedings over the past three decades, and we have extensive experience in both the written and oral hearing stages.


We have an office in Munich which can be used as a base for the many Opposition Division oral hearings, held at the EPO’s offices there.


We provide commercially-focussed advice throughout the process helping you to defend your patent or have your competitor’s patent revoked or restricted in scope.


Introduction of the Unified Patent Court in Europe

The Chartered Institute of Patent Attorneys has released a video explaining the upcoming changes to the patent system in Europe and the introduction of the United Patent Court on 1 June 2023.


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