29 September 2023
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The Unified Patent Court (‘UPC’) opened its doors on 1 June 2023. It is a new court in the European Union (‘EU’). It provides a forum for litigating patents granted by the European Patent Office (‘EPO’) that have been validated as either:

  1. Unitary Patents (‘UPs’); or
  2. standard European Patents (‘EPs’) in a Contracting Member States that have, additionally, not been “opted-out” of the court. 

A claimant at the UPC has the power to enforce their UPs or EPs in all the contracting states where infringement is occurring (and, for EPs, where they are also validated), instead of having to bring separate patent infringement actions in each such country. There are currently 17 contracting states, including key patent jurisdictions such as Germany, France, The Netherlands, and Italy. A further 7 EU countries may join the UPC once they ratify the UPC Agreement (‘UPCA’). Spain, Poland and Croatia have decided not to join the system. Also, key EP countries outside the EU, such as the United Kingdom and Switzerland, cannot join. Thus, parallel litigation in multiple European countries will still be necessary in some cases.

In a similar vein, a defendant at the UPC will have the power to seek “central” revocation of a UP or EP, that is to say, to have the patent revoked in all the contracting states by one action, rather than through a number of separate revocation actions via national procedures. Note that an earlier unsuccessful EPO opposition does not estop this right to seek central revocation later.

A focus on written submissions 

For those interested in bringing an action at the UPC, and of course for those defending against such actions, there is one really key feature of the court to be aware of: it is incredibly front loaded, especially in comparison to proceedings in the US, the UK and other common law jurisdictions, and the bulk of the case has to be set out in writing. The oral hearing will not be an opportunity to argue your case, and cross-examination the other side’s case is likely to be very limited. The hearing is likely to be inquisitorial, that is, led by the judges to clarify points in the written submissions of the parties. 

The claimant, therefore, has to prepare their entire action up front, which is not just their pleadings, but also the facts relied, all known evidence (although they can request access to further evidence but not disclosure per se) and their legal arguments. Obviously, this will also front-end most of the legal costs. Critically, however, because they control when they file their action the claimant has time – time to prepare their action and also time to prepare for any likely counterclaim. A defendant on the other hand, only has 3 months from the date of being served with the action (and there is no requirement to undertake pre-action correspondence with the other side) to: 

  1. file their defence – which, as for the claimant, must cover their pleadings, their facts, evidence and legal arguments, and
  2. file any counterclaim, again, including their pleadings, their facts, evidence (including prior art searches, analysis and expert reports) and legal arguments.

The defence to counterclaims, replies and responses that follow from the initial pleadings all allow the receiving party less time to respond, going from 3 months to 2 months and then 1 month.

Preparation involving a team competent on all fronts is key

You will appreciate, therefore, that in a court with such tight deadlines, front-loaded submissions, and a focus on the written submissions, plus an aim to complete all actions filed within a year or so, that being subject to an action without any prior preparation will potentially be very disadvantageous. 


  1. If you believe a party may be infringing your UP or EP in a CMS, and you are contemplating a UPC action, you should not only carefully prepare your claim pleadings carefully and thoroughly (and avoid tipping off the defendant), but you should also prepare for any invalidity counterclaim. You may not be able to anticipate all possible lines of attack, but even preparing for the likely attacks will be very advantageous. You could even undertake some preparatory prior art searching to identify any key documents you are not currently aware of.

  2. If you suspect you may be the subject to a UPC infringement action, perhaps because of a prior history with the claimant or knowledge that your goods or services are close to their patented rights or a careless tip off from the claimant, some basic preparatory defence work and work on potential invalidity counterclaims, including prior art searches and analysis, could be a game-changer in improving your chances of success in the action. Considering some strategic options for running the litigation could also pay dividends. 

    You should also file a “protective letter” at the UPC. Such a letter may protect you against a preliminary injunction or other ex parte procedure that the claimant seeks in the first instance. You should do this even if the EP is “opted out” of the UPC. A claimant can withdraw their opt-out at short notice in order to file an action at the UPC, provided that the patent has not or is not currently being litigated before a national court. (This is a way they can protect themselves from a pre-emptive central revocation action before they are ready – see next paragraph.)

  3. If you are concerned about some blocking patents, and you are considering a pre-emptive “clearance” revocation action at the UPC, in a counter-pose to item (2), you should prepare for an infringement counterclaim, for example lining up counter-arguments on likely infringement claims, preparing expert reports, and so on.

Looking forward 

The UPC is still very new. There have been just over 50 cases filed since June. Parties that are well-prepared, including for the counter-punch, are likely to benefit from a strong advantage in any actions at the court. Some effort now, could pay dividends in the future. If you would like to discuss any of the above, please reach out to your usual Mewburn Ellis contact or to Dr Sean Jauss, head of our legal services department.


Guide to the Unitary Patent and Unified Patent Court-2

The Unitary Patent and the Unified Patent Court - A guide

Find out more about the Unitary Patent and Unified Patent Court with our detailed guide. This covers a summary overview of both as well as details around costs and processes to obtain a unitary patent and a comparison of pros and cons.

We can handle all aspects of litigation at the UPC, both offensive and defensive actions.

Download here


Sean is head of our legal team and dispute resolution teams and a member of our Management Board. He has over 15 years of experience advising on contentious and non-contentious IP matters, including patents, trade marks, designs, copyright, database rights and trade secrets across a range of industry sectors. He works closely with senior management and their external counsel to deliver a wide range of IP related projects in a pragmatic and commercially-focussed manner, including on IP protection, commercialisation, technology transfer and dispute resolution.

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