European Opposition Procedure

If you are interested in applying for a European Patent, you need to be familiar with the post-grant administrative proceeding known as the European Patent Office (EPO) Opposition Procedure. This is the process by which someone (anyone, regardless of commercial interest) is able to challenge, or oppose, a European Patent after grant. One of the attractive features of this procedure, in addition to the relatively low costs of filing, is the ability to oppose a patent and have the result be applied to all applicable European countries (as many as 38). 

Timeline for European Opposition

After a patent has been granted by the EPO, an opposition may be filed within nine months of publication in the European Patent Bulletin. This deadline usually cannot be extended. The opposition must be filed in writing in certain designated locations in Europe. After that nine-month period has passed, the patent holder then has four months to file a response, or counterstatement. After that, either side may be entitled to submit further briefs on the issues. 

Eventually, an oral hearing is scheduled, at which both sides will be able to present arguments before the Opposition Division. At the conclusion of the hearing a decision as to patentability is made, followed by a written decision. All told, the entire European Opposition process will take a minimum of 18 months. Around one-third of oppositions last longer than three years, even after the initial nine-month period for oppositions to be filed. 

Grounds for Opposition

After an opposition has been filed before the EPO’s Opposition Division, it will need to be determined whether or not an opposition actually exists. If the conditions are satisfied for the opposition to be filed, it will then be scrutinized to determine whether or not the opposition is admissible. The following are some accepted grounds for filing a European Opposition: 


  • The subject matter is not patentable based on prior art;
  • Insufficient disclosure of the invention that does not allow a skilled person to use it;
  • The subject matter extends outside the bounds of the application’s content


Potential Outcomes of the Process

If an opposition of a European Patent is successful, then the patent will either be revoked or limited in the applicable nations. If the opposition is dismissed, then individual countries might still pursue revocation of the patent in question. The decision of the EPO’s Opposition Division may be appealed. 

Contact Attorney Jim Cartiglia

The European Opposition procedure is not familiar to all American patent practitioners, so you need an intellectual property attorney with experience dealing with the European Patent Office and its Opposition Division. Attorney Jim Cartiglia of OspreyIP can help with that and a wide variety of other intellectual property matters. To get in touch, please call the firm at 615-523-9955.

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OspreyIP, PLLC

Based in Brentwood, Tennessee, OspreyIP is a law firm that operates internationally to help clients file and prosecute patent applications, secure trademark registrations, and take steps to protect their intellectual property.

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