There are several ways to invalidate an issued patent. A patent may be invalidated through opposition proceedings at the patent authorities or through invalidation proceedings in court.

In most jurisdictions – including Europe and US – an issued patent may be invalidated through opposition proceedings at the patent offices. Normally an opposition shall be filed within a deadline varying from 2 to 9 months from the issuance of the patent.

Additionally a patent may be invalidated in invalidation proceedings at court. Invalidation proceedings may be separate proceedings or be part of infringement proceedings at court and may be filed at any time after issuance of the patent.


In order to successfully invalidate an issued patent it is necessary to show that the patent does not fulfil the criteria for patentability, in particularly by lacking novelty or inventive step. We assist in the analysis of validity of any blocking patents, in order to identify dominating patents and solutions to avoid or fight the blocking effect.

We have competence and experience in invalidation proceedings and assist the whole way through the proceedings from the first analysis through optional negotiations with the patentee to a lawsuit.

Our experience ranges from opposition cases at the European Patent Office to lawsuits at national Danish courts as well as foreign courts.

HØIBERG is the Danish IP company conducting most oral proceedings in opposition proceedings with the European Patent Office. In addition we assist our clients in Danish IP lawsuits, and several of our partners are appointed court experts and technical judges.

Relevant products"Invalidation"

Our services are often sold as packages ranging over a number of fields. Please choose a package below and read more about the typical course of action ...