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EPO Oppositions & Appeals

Oppositions at the European Patent Office (EPO) are a relatively low-cost means of getting a European patent revoked across all of the European countries in which that patent has effect. Consequently, EPO oppositions can be important for securing a competitive advantage, especially when used to invalidate a competitor’s European patent.

EPO Oppositions Schlich UK



The EPO allows third parties to challenge its decision to grant a European patent for a short period of time after that patent has been granted. If successful, an opponent may convince the EPO to revoke the patent, or at least get the proprietor to amend it, which can be vital for the opponent’s commercial strategy. EPO opposition proceedings are much cheaper than challenging validity of a patent in the courts, and the result of the opposition proceedings takes effect in all of the European countries in which the patent has effect. This means EPO oppositions are very attractive to those wishing to have a European patent invalidated.

To oppose a European patent, the opponent has to present its case to the EPO within 9 months of the grant date of the patent. The EPO will then give the proprietor of the patent an opportunity to respond within about 4 months of being informed that an opposition has been filed. The EPO’s Opposition Division will then consider the arguments put forward by each side, and will usually then issue its preliminary, non-binding opinion on the pertinent issues. In many cases, both sides will then be set a deadline for filing further written arguments and evidence, and there will normally then be an oral hearing for both sides to present their arguments to the Opposition Division directly. The Opposition Division will then decide on the matter, and a written decision (i) maintaining the patent as granted, (ii) maintaining the patent in amended form, or (iii) revoking the patent altogether will be issued shortly afterwards.

Whilst the exact time EPO oppositions take to complete can vary depending on the complexity of the case and the number of parties involved, an approximate timeline for these types of proceedings is illustrated below.

We have a wealth of experience in oppositions before the EPO, both in terms of defending our clients’ patents from attacks by opponents and attacking the patents of our clients’ competitors. Our team is accustomed to handling high-value, complex proceedings and is, for example, currently involved in attacking a collection of highly valuable, cutting-edge life sciences patents relating to the revolutionary gene-editing technology known as CRISPR/Cas9.

If there is a European patent that you want revoked, then we would be happy to work with you to file an opposition at the EPO. Similarly, if your European patent is under attack from your competitors and you would like our help defending it, then we would be happy to work with you to fend off that opposition, as well.

EPO oppositions can be filed anonymously, and thus if you are concerned about your competitors learning that their European patent is problematic for you, then we can file the opposition in our name, avoiding the need to identify you at any stage.





European Patent Granted



Opposition Filed



EPO Invites Proprietor to Respond



Proprietor Files Response



EPO Issues Summons and Preliminary Opinion



Deadline for Making Final Written Submissions



Oral Proceedings and Verbal Decision



Written Decision Issued

EPO Appeals



Sometimes, the EPO’s Examining Division may refuse one of your European patent applications, or the EPO’s Opposition Division may reach a decision that is not in your favour. Fortunately, those adverse decisions can be appealed to the EPO’s Boards of Appeal, where you have an opportunity to have that decision overturned. Convincing the Boards of Appeal to overrule the Examining and Opposition Divisions is no easy task but, with our team’s technical and legal know how and years of experience representing clients in these types of proceedings, we have handled a large number of EPO appeal cases with successful outcomes.

To appeal a decision of the EPO, the appellant must file notice of that appeal within 2 months of the decision being issued. Within 4 months of the decision being issued, the appellant has to set out the grounds on which its appeal is based. In the case of appeals arising from opposition proceedings, the EPO will then notify the other side that an appeal has been filed, giving the other side approximately 4 months to file a submission in response. Typically, the EPO will then issue a preliminary, non-binding opinion on the arguments presented, and will summon the parties to an oral hearing to present those arguments further. A decision will be taken on the matter at the oral hearing, and written reasoning for that decision will then be issued by the Board of Appeal within the next few months.

We frequently represent clients who want to appeal a decision of the EPO that hasn’t gone their way and, with our team’s specialist expertise regarding a variety of different technologies, we are well-placed to help you challenge a decision that has gone against you, too.

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Carolyn Palmer - Schlich

Our team of UK and European Patent Attorneys and Chartered Trade Mark Attorneys are highly knowledgeable and experienced in assisting clients with all aspects of their IP needs.

Contact us now to find out more about how we could help you and your business.