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A Comprehensive Guide About Patent Infringement (2023)

Curious about patent infringement litigation in Germany? Is your competitor infringing your patent? Or your competitor claims you are infringing his patent? You don’t know where to sue your competitor? To date, German courts decide more than half of all patent infringement cases in Europe and more than 10 times as many cases as the UK. Want to know why?

This is a very comprehensive guide to patent infringement litigation in Germany – for both the plaintiff and the defendant. The article explains in detail how to enforce patents and how to defend against a patent infringement lawsuit. Here is a brief outline of the article for better navigation:

Introduction to Patent Infringement Proceedings

In the field of intellectual property, patent infringement remains a central concern. Germany, a nation known for its robust patent system, hears more than half of all patent infringement cases in Europe. This guide delves into the intricacies of patent litigation in Germany, contrasting it with the newly established Unified Patent Court (UPC) and offering insights for both plaintiffs and defendants. It is no coincidence that more than half of the judges on the newly opened Unified Patent Court are German.

Patent infringement in Germany, as in other jurisdictions, refers to the unauthorized use of a patented invention. However, the German patent system has unique aspects that set it apart. For example, the German Patent Act provides specific definitions and doctrines related to patent infringement.

If you want to hear about patent litigation from an industry perspective, you can listen to my interviews with e.g. Ralf Uhrich, Senior Patent Litigation Counsel of Google Overseeing All Patent Litigation for Google in Europe, Beat Weibel, Chief IP Counsel of Siemens, or my interview with Gabriele Mohsler – VP Patent Development at Ericsson.

Understanding Patent Infringement: The German Perspective

In Germany, patent infringement encompasses unauthorized actions concerning a patented invention. The German patent system, rooted in its rich legal tradition, offers specific definitions and doctrines related to infringement. For instance, while the German Patent Act delineates the boundaries of infringement, the UPC, spanning multiple European jurisdictions, brings in a harmonized approach, albeit with its nuances.

The Patent Infringement Process in Germany: A Detailed Overview

Germany’s patent process is multifaceted. From filing the patent to the final verdict in an infringement case, each step is meticulously defined. In contrast, the UPC, aiming for a unified European patent litigation system, streamlines certain processes, potentially offering swifter resolutions. The following sections provide a detailed introduction.

Implications for Stakeholders: Navigating the Dual Landscape

While plaintiffs in Germany seek to enforce their patents leveraging the nation’s stringent laws, defendants often explore avenues to challenge patent validity. With the UPC in play, stakeholders now have to strategize considering both the German system and the broader European framework.

International Implications: German Patents Beyond Borders

German patents can be extended to other countries within the priority term of 12 months. PCT applications can be filed. A patent application can be filed with the European Patent Office or most other national patent offices. However, with the UPC, cross-border enforcement within member states becomes more streamlined, albeit with distinct differences from the German-only system.

The UPC’s Influence on German Patent Infringement Litigation

The UPC’s establishment aims to offer a unified patent litigation system for Europe. While it streamlines processes, it also introduces complexities, especially when juxtaposed with Germany’s established system. Stakeholders need to be aware of the differences and potential overlaps.

What is the statute of limitations on patent infringement in Germany?

In Germany, the statute of limitations for patent infringement claims is 3 years. The period begins at the end of the year in which the patent holder became aware of the infringement and the infringer, or would have become aware without gross negligence. However, regardless of knowledge or grossly negligent ignorance, claims expire 10 years after the infringement occurred. It’s important to consult with legal counsel for specific cases, as nuances and specifics can vary based on individual circumstances.

What is the §139 German Patent Act?

§139 of the German Patent Act defines some of the claims that a patent owner can bring against an infringer. Any person who uses a patented invention without the consent of the patent owner may be sued by the infringer for an injunction if there is a risk of repetition. The claim also exists if an infringement is threatened for the first time. The claim is excluded if the claim would lead to disproportionate hardship for the infringer or third parties not justified by the exclusive right due to the special circumstances of the individual case and the requirements of good faith. In this case, the infringed party shall be granted appropriate compensation in money. The claim for damages below remains unaffected thereby. Any person who performs the act intentionally or negligently is obliged to compensate the injured party for the resulting damage.

Assessing Damages

In assessing the damages, account may also be taken of the profit made by the infringer as a result of the infringement of the right. The claim for damages may also be calculated on the basis of the amount that the infringer would have had to pay as reasonable remuneration if he had obtained permission to use the invention. If the subject matter of the patent is a process for the manufacture of a new product, the same product manufactured by another is deemed to have been manufactured by the patented process until the contrary is proved. In proving the contrary, the legitimate interests of the defendant in the protection of his manufacturing and trade secrets shall be taken into account.

Decoding Technical Terms in Patent Infringement Proceedings: Bridging the Knowledge Gap

  • Patent Litigation: Patent litigation is the legal process in which a patent holder seeks to enforce their patent rights against an alleged infringer through a lawsuit in a court of law.
  • FTO Search: An FTO (Freedom to Operate) Search is a comprehensive examination of issued patents and pending patent applications to determine if a product, process, or technology can be commercialized without infringing on existing patent rights in a specific region or country.
  • Patent Licensing: Patent licensing is the process by which a patent holder grants permission to another party to use, manufacture, sell, or distribute the patented invention, typically in exchange for royalties or other compensation.
  • Doctrine of Equivalents: The Doctrine of Equivalents is a legal principle in patent law that allows a court to find patent infringement even if the accused product or process does not fall within the literal scope of a patent claim, but performs substantially the same function in substantially the same way to achieve substantially the same result as the claimed invention.
  • Direct Infringement: Direct infringement is the unauthorized making, using, selling, offering for sale, or importing of a patented invention, without the patent holder’s permission, in a jurisdiction where the patent is in force.
  • Contributory or Indirect Infringement: Contributory or Indirect patent infringement occurs when a party aids or abets another in the unauthorized use of a patented invention, typically by supplying a non-infringing component with the knowledge that it will be used in an infringing manner.

Patent Infringement Example Case: Moderna’s COVID Patent Litigation Situation

Moderna, Pfizer, and BioNTech have been at the forefront of the COVID-19 vaccine race, with their mRNA-based vaccines receiving global acclaim. However, their success has also brought them under the legal spotlight, with several companies alleging patent infringements related to the underlying mRNA technology and lipid nanoparticle (LNP) delivery systems.

Promosome’s Allegations

New York-based Promosome has filed lawsuits against both Moderna and Pfizer, accusing them of violating patent protections related to mRNA technology. Promosome claims that its affiliated scientists discovered a method in 2009 for increasing protein expression by making small changes to the mRNA. This method is protected by U.S. Patent No. 8,853,179, also known as the ’179 Patent. The company alleges that both Moderna and Pfizer/BioNTech used Promosome’s patented method to produce their COVID-19 vaccines. As compensation, Promosome seeks a “reasonable royalty” from the revenues of the COVID-19 vaccines developed using their technology.

Arbutus and Genevant’s Claims

Arbutus Biopharma and Genevant Sciences have previously filed lawsuits against Moderna, alleging that the company infringed on patents related to nucleic acid-lipid particles and lipid vesicles. The core of the lawsuit suggests that Moderna, despite licensing Arbutus’ LNP patents for other projects, did not do so for its COVID-19 vaccine, Spikevax.

Alnylam’s Allegations

Alnylam, an RNA interference specialist, has also filed lawsuits against both Moderna and Pfizer. The company alleges that it was primarily responsible for the LNP technology used in its RNAi therapeutic, ONPATTRO, and accuses both Moderna and Pfizer of patent infringement.

Moderna vs. Pfizer and BioNTech

Moderna has also initiated legal action against Pfizer and BioNTech, accusing them of unlawfully copying Moderna’s mRNA inventions. In response, Pfizer filed a countersuit seeking to dismiss Moderna’s claims.

Financial Implications and Conclusion

In 2021, Pfizer/BioNTech’s COVID-19 vaccine, Comirnaty, generated nearly $37 billion in revenue, while Moderna’s Spikevax earned $17.7 billion. None of the companies alleging patent infringement are seeking to halt the production or distribution of the vaccines. However, they are pursuing a share of the revenues earned by Moderna, Pfizer, and BioNTech. The ongoing patent litigations highlight the complexities surrounding the development and commercialization of groundbreaking medical technologies. As these cases progress, they could have significant financial and reputational implications for all parties involved.

Patent Infringement Example Case: Panasonic’s Patent Litigation Against Oppo and Xiaomi Before the Unified Patent Court (UPC)

Panasonic, a renowned Japanese electronics company, has initiated legal actions against Oppo and Xiaomi, two prominent smartphone manufacturers. The core of the dispute revolves around alleged patent infringements related to 4G smartphone technology.

  • Licensing Agreements: Panasonic claims to have successfully reached licensing agreements with various smartphone companies. However, despite years of negotiations, they failed to finalize such agreements with Xiaomi and Oppo.
  • Multiple Jurisdictions: The lawsuits against Xiaomi and Oppo are not limited to the UPC. Panasonic has concurrently filed cases in China, Germany, the UK, and the Unified Patent Court of the European Union.
  • Number of Claims: Panasonic has filed seven infringement claims at the Unified Patent Court against various subsidiaries of Oppo and Xiaomi. These claims mark some of the first major cases at the UPC, highlighting the significance of the dispute.
  • Nature of the Dispute: The primary contention is related to 4G technologies. Panasonic alleges that both Oppo and Xiaomi have used its patented 4G technology in their smartphones without obtaining the necessary licenses or permissions.

The ongoing patent litigation between Panasonic, Oppo, and Xiaomi underscores the complexities surrounding intellectual property rights in the rapidly evolving tech industry. As the cases progress, they could set precedents for future disputes, especially within the framework of the Unified Patent Court.

The Unified Patent Court (UPC)

The Unified Patent Court (UPC) and the Unitary Patent system have emerged as transformative entities in the European patent landscape. This section provides a concise overview of the UPC and the Unitary Patent, drawing from authoritative sources to present a comprehensive understanding of these institutions. I had the chance to interview Dr. Klaus Grabinski, President of the Court of Appeal of the Unified Patent Court System, just before the launch of the UPC. You can listen to the full interview.

The UPC has just opened its doors. However, we can already see the trend that more than 50% of all judges are German and more than 50% of all cases are in German language.

Introduction to the Unified Patent Court (UPC)

The UPC is a specialized patent court with jurisdiction over all European patents (EPs) designated to participating EU Member States that have ratified the UPC Agreement (UPCA). As of now, 17 EU Member States, including Austria, Belgium, Bulgaria, Denmark, Estonia, Finland, France, Germany, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Portugal, Slovenia, and Sweden, have ratified the UPCA. Notably, Spain, Croatia, and Poland have chosen not to participate, while the UK initially participated but later withdrew.

The Unitary Patent (UP)

A Unitary Patent (UP), also known as a European patent with unitary effect, is a single supra-national patent right covering all the EU Member States participating in the enhanced cooperation and have ratified the UPCA. The option to select a unitary effect became available with the establishment of the UPC. A unique feature of the UP is that its territorial coverage is determined by the UPCA participating member states at the time its unitary status is granted.

Jurisdiction Dynamics

The UPC holds exclusive jurisdiction over UPs and EPs that haven’t been opted out of its purview. However, during a transitional period, national courts will retain jurisdiction over non-opted-out EPs. This transitional period is set to last a minimum of 7 years, with a potential extension of another 7 years based on a mid-term assessment. EPs can be opted out (or back in) during this period. Once the transitional phase concludes, EPs granted after this period will fall exclusively under the UPC’s jurisdiction.

Structure of the UPC Court System

The UPC comprises three types of first-instance courts:

  • Local divisions in participating states
  • Regional divisions
  • A central division with three seats in Paris (main seat), Munich, and Milan.

The central division handles specific cases based on the subject matter of the patents involved, determined by International Patent Classification (IPC) classifications. Notably, the “London” seat, which was initially assigned cases related to human necessities and pharmaceuticals, was reallocated to Milan following the UK’s withdrawal from the UPCA.

Choosing Between EPs, UPs, or National Patents

European patents (EPs) are applied for at the European Patent Office (EPO) and, upon grant, are converted into a bundle of national patent rights. In the UPC era, applicants can opt for an EP with unitary effect (UP) or continue with traditional EPs for non-UPC participating states. For a transitional period, EP proprietors can opt out of the UPC system, post which all non-opted EPs will be under the UPC’s jurisdiction. National patents (NPs) remain an option for those wanting to bypass the UPC system.

The Evolution of the UPC and UP

The UPC and UP became a reality on 1 June 2023. Regulation 1257/2012, which established the UP, was in force for some time, but the grant of UPs awaited the full establishment of the UPC. The first UP could only be granted post 1st June 2023.


The establishment of the Unified Patent Court and the introduction of the Unitary Patent mark significant milestones in the European patent landscape. These entities aim to streamline patent litigation and provide a unified approach to patent rights across participating EU Member States. As the system evolves, it will be crucial for stakeholders to stay informed and adapt to the changing dynamics of patent protection in Europe.

Patent Litigation Statistics in Europe

Germany leads in patent litigation, but with the UPC’s inception, a shift in patent litigation dynamics is anticipated. Current data suggests Germany handles 60% of Europe’s patent cases. However, the UPC’s influence might redistribute these numbers in the coming years.

In this section, I will dive into some interesting statistics on patent infringement in Europe. The full details of this section have been published in an article in the magazine The Patent Lawyer in the March/April 2015 issue. I had co-authored the article with Dr. Thomas Kuehnen, presiding judge of the patent infringement chamber of the Higher Regional Court of Duesseldorf. This is the busiest court for patent infringement in Europe (Kuehnen/Claessen “The enforcement of patents in the EU”, The Patent Lawyer, March/April 2015, p. 15; also Kühnen/Claessen, GRUR 2013, 592). Our office is only around 1 km away from this important court.

The Numbers

Out of about 2,000 patent infringement cases, more than 1,200 cases are handled by German courts. For comparison, Great Britain has around 50 yearly cases. And France, as the second most important country, has a little less than 300 cases per year. And there are actually 14 countries in the EU where there are no patent infringement cases at all.

Why Germany?

What makes Germany so interesting for plaintiffs? First of all, the first instance ruling is typically delivered within a year. The second instance takes only one more year. And if people choose to try the third instance, the Federal Court of Justice in Karlsruhe, it will typically take another 3 years on average. All three instances in 5 years are very quick in comparison with the other EU countries. Another reason may be the comparatively low cost. The losing party has to refund the costs of the winning party and these costs are capped by law. The typical cost risk for the first instance for lawyer fees of both sides and court fees together is about 60,000 to 100,000 EUR. This depends on the value of the case.

As for the first instance, the Regional Court of Duesseldorf handles around 500 cases per year. The courts in Mannheim have around 265. The court in Hamburg handles around 180 cases. The court in Munich handles around 150 cases. Other important courts are Nuremberg, Berlin, and Frankfurt. These numbers are dated 2011.

One interesting fact is the bifurcated system in Germany. The patentability is handled by the Federal Patent Court in nullity actions or by the German Patent and Trademark Office.

The Plaintiff Before the Complaint

You found out that a competitor is selling or producing your patented product in Germany. In this section, you find out what you can do as a plaintiff to maximize your chances in a patent infringement case in Germany.

Collecting Evidence

So you start of course by collecting evidence. The biggest difference between Germany on the one hand and the UK, France, and the US is that you have limited discovery abilities. If you have a method or process claim, you can ask a court for a preliminary injunction with the aim of inspecting the process or the method of a potential infringer. But you cannot do that by yourself or by your attorneys. You have to send an independent court expert and you have to give the court expert some homework on what exactly to look for.

An example for a todo list for such expert: to press buttons on different machines, look at the recipes, or have a USB stick inserted into computers and copy the relevant files for the method or process. So the possibilities are quite limited and you have to make sure that you are aware of this. In some instances, you can use discovery evidence from other countries and litigation proceedings. If you have already made some discovery in, let’s say, the UK, France, or the US, you can in some cases use that evidence in Germany as well.

Cease & Desist Letter

Typically, first, you want to send a cease and desist letter. You do that to avoid a cost risk. You have to know that in Germany the loser pays all costs. So if you lose your case, then you have to pay the attorney and court fees, also of the other party. So to limit that risk, you should file a cease and desist letter first. Because even if you win, and the potential infringer says in court: “Well they didn’t warn me – if they had warned me I would have immediately stopped”. Then you get a positive decision by the court but you have to bear all the costs of the procedure. To avoid that you would send a cease and desist letter.

You may want to set a quite short timeframe, like one week, which is probably the shortest fair period that you can use. Sometimes I also use two weeks, to be fairer. But one week is probably the shortest in patent cases because patent cases are quite complicated cases.

Preliminary Injunction

So if you want to stop somebody immediately you can do something that is particular to Germany and the UPC. You can file a request for a preliminary injunction. Typically that is used with designs or trademarks, but that works for patents as well. Sometimes these requests are granted. You have to understand that a preliminary injunction means that you file a request with a court and within sometimes one day, two days or three days, the court decides, that the potential infringer has to stop selling, producing, or offering the product in Germany immediately. So that is quite a sword that you can use, a weapon. And if you are wrong, you have to pay a lot of damages. So you have to really be careful whether you want to use this weapon.

Also, it’s difficult to convince the courts, since patent cases are quite complicated, and also the validity of the patent is not always clear. Some courts are granting preliminary injunctions. So you can try. You cannot be sure that you get this granted at least not without oral proceedings, hearing the other party.

Preparing the Complaint

Then preparing the complaint is quite similar to other legislation. When I became a patent attorney some time ago, I did an internship with the judges in Dusseldorf – the patent judges. And I found out how they deal with patent infringement cases. How they assess patent infringement. One tool they use is the following. They mark the claim with colors – the features in the claim with colors. Then they get a figure, depiction, or image of the infringing product, and mark the corresponding features in the infringing product with the corresponding color of the claim, to understand, whether something is infringing or not.

So if you can provide this marked-up claim with the corresponding depiction to the judges with the complaint, that probably helps your case because you can use the colors as you would like the judges to use the colors. So you can basically mark the features in the infringing product the way you would like the judges to interpret the claim. I have an example in the video.

Filing the Complaint

Then, last but not least it’s important to know where you want to file your complaint. Each state in Germany has defined one or two courts, where you can file patent infringement complaints. And I already mentioned that only a couple of courts have a lot of experience, for example, Dusseldorf, Munich, Mannheim, and Hamburg. The other courts do not really have a lot of patent infringement cases. On the other hand, you have to know that the larger and more important courts, as I’ve mentioned, also have a quite quick turnaround. Typically you’ll get your first instance ruling within one year. And a second instance ruling within another year.

Patent Infringement: The Defendant Before the Complaint

An example: you are launching a new pharmaceutical product in Germany and there is a patent that you are aware of that is very similar to your product. Then you might want to take precautionary measures to increase your chances of success in potential patent litigation in Germany.

Preliminary Injunction

What do you have to fear as a potential defendant in a patent litigation case in Germany? Of course, there can be a complaint but also more importantly in Germany, it is possible to get a preliminary injunction for plaintiffs on very short notice. So, a plaintiff can request a preliminary injunction with a court and the court might decide within one, two, or three days to issue a preliminary injunction and you would have to stop offering, producing, or selling your product immediately. Then there is – of course- the chance that you get a cease and desist letter.

Prior Art Search

One strategy can be that you search for prior art and see whether you can invalidate the patent. In the first step, you do not really have to file any invalidation proceedings with the Bundespatentgericht, the Federal Patent Court, or file your arguments later in the patent litigation case. Rather you can basically make a draft for a cancellation action against the patent and you can send this draft to the patent owner and ask them for a free right to use the patent in exchange that you do not attack the patent with the enclosed draft.

If you have good prior art and good arguments, the patentee might start discussing with you. The patentee, of course, wants to keep the patent to be able to go after other infringers. They might give you the right to use the patent and not file any complaint against you. This strategy, of course, has its weaknesses. If you are asking the patentee, then you are basically telling the patentee that you are possibly infringing their patent. So, you have to be very sure. It has to be a quite clear case that you can invalidate the patent. Otherwise, it would not be really useful to use this strategy.

Protective Letter – Schutzschrift

What can you do to counteract the preliminary injunction? You can file a protective letter (“Schutzschrift”) with the relevant courts and the electronic registry for protective letters in Germany. In this protective letter, you would outline your arguments against patent infringement. So, basically non-infringement arguments and invalidity arguments against the patent – just enough to make the court think twice before issuing a preliminary injunction. Keep it to the point, concise, and under 20 pages if possible. I have discussed with a couple of judges that they do not really like too many pages. So, if you can keep your protective letter short, it is probably a wise decision.

If you are aware of a patent that you could be infringing, then file a protective letter with the respective courts before launching a product or at the latest at the launch date.

Measures to Take Before Launch of a Product

Then finally, think about instructions to the people at the doors of your premises. In Germany, it is also possible to have some limited way of discovery, a discovery process, where an independent court expert can appear at the doors of your offices or manufacturing locations or research facilities and they can request to look at your product or especially your process and methods that you are using. The people at the door might not be well prepared to handle this kind of situation. So, before launching a new product, you might want to make one-page information, not more, for the people that are guarding your doors of the different locations, where you basically state in case there is an independent expert from the courts what they would have to do.

For example, let them ask for their permit, the permission by the court that they can search your facilities. If they do not have that permit, then they would have to go back to the court and ask for permission to enter the premises. Then you can ask them for two hours time to wait until you have an attorney on-site. Then, of course, you want to ask the doorman, the person at the door, to seat the independent expert in the waiting room until the attorney is there and watch the independent expert. There may be other very useful instructions. Just send us a quick email for more information.

Patent Infringement: The Plaintiff After Filing the Complaint

First, I want to give you an overview of the overall procedure. Most times, there will be a first short hearing which will last only about five to 10 minutes. In this first hearing, the requests of the parties and especially the defendant will be heard and the dates will be set for the response of the defendant and the replication of the plaintiff and then, of course, the date for the main hearing will be set. So, in this first hearing, do not expect too much. It will just be five minutes where the judge basically just asks the parties for their requests and where the judge will set the different time limits and the dates.

Make It Easy for the Court

So, what can you do before a court in German patent infringement cases? Maybe some general remarks. The judges really do not like to read more than about 20 pages. So try to be concise, try to be brief. Do not use font size below 10 points, preferably a little larger. Do not use single-space lines. Give the lines a little room to breathe. Do not set the margins to two millimeters – leave some margins. That is especially important because the judges like to make notes on the margin. So leave them some room for them to make notes in your submissions.

Then you would have to file translations for anything that is not German, so that is important because otherwise the material cannot be used or may not be used.


And then there is another specialty in Germany. As you may know, the costs for the attorneys and for the court are set by the value of the case. They are defined by the Attorney Remuneration Act (Rechtsanwaltsvergütungsgesetz) and so, if your client asks you to be less expensive, then, of course, you could just use a very low value of the case. But that has backfired a couple of times in the past. So judges have said “You Shall Not Lie”, especially Judge Thomas Kuehnen. In Dusseldorf, there were several decisions that were named “You Shall Not Lie”. So do not use a value of the case that is much lower than it should be. Otherwise, the judges will just set the value of the case to a much, much higher value.

Main Hearing

So, how does the main hearing go? In the main hearing, the presiding judge will give you the preliminary opinion of the court, and he will also lay out the points that are of interest to the court. In your pleadings, stick to these points. That is my suggestion. Because otherwise, you are boring the court. The court wants an answer to exactly these points, so be kind to the court and focus on these points. If you really think there are one or two other important arguments, then go ahead and argue these points. But be sure that you watch the judges whether they appreciate these additional points that you are making. The main hearing will last probably one to three hours and maybe some experts or witnesses are called.

One thing you have to know is that there can be literal infringement and infringement under the doctrine of equivalence. So if you are the plaintiff, then you want literal infringement. Try to find good arguments for literal infringement. Otherwise, it might be easier for the defendant to evade a favorable decision for the plaintiff.

Validity Not Assessed By Infringement Court in Germany

One other point that is important in Germany: the judges in patent infringement cases do not really judge about the patentability of the patent, the validity. So they will decide on infringement. The validity of the patent will be decided by the Federal Patent Court. So in some cases, the judges will stay the proceedings if there are parallel revocation proceedings. And sometimes they do not. So that would be good luck for you as a plaintiff.

Patent Infringement: The Defendant After Filing of the Complaint

In the previous section, I gave you some general remarks and tips about the overall procedure, the hearings, and the different deadlines. So if you want to know more about that and tips, general tips about patent infringement in Germany, then go to the previous section.

Security of Costs

What can you do as a defendant? First of all, you can ask for the security of costs for non-EU plaintiffs. That can be very efficient. If the plaintiff cannot deliver this security, then the whole case is moot. You can also immediately acknowledge all claims of the plaintiff if the plaintiff did not warn you or send a cease and desist letter. Then the costs of the whole proceedings will be shifted to the plaintiff.

Validity of the Patent

Of course, you can challenge the validity of the patent with opposition proceedings or a revocation action (“Nichtigkeitsklage”) before the Federal Patent Court. That can be very efficient. The German system is bifurcated. So sometimes, the infringement court will stay the proceedings until there is a decision in the revocation action.

Limit the Scope

One other strategy is about making the judges limit the scope of the claims to basically the drawing or the example given in the patent. You have to know that some judges are coloring the features in the claim and also in a depiction of the infringing good. They may be marking the features in the infringing good with corresponding colors. You can get a drawing from the patent, where the features are shown, and color them in the corresponding colors of the colors that you used in the claim for the various features. Sometimes the court will use these drawings to interpret the claims. And then, naturally, sometimes the interpretation of the claims will be very narrow. So that can help you as well.

Formstein Defense

One other defense that I want to mention is the so-called Formstein defense. If you are working within the prior art, you cannot literally infringe a patent. That has been decided by the Federal Court of Justice in Germany a long time ago. So if you find yourself working within the prior art – you find a good piece of prior art that exactly describes what you’re doing – then maybe you can defend yourself with the Formstein defense.

Moving Literal to Equivalent

Then another strategy is to find good arguments to move the argument from literal infringement to infringement under the doctrine of equivalence. That way you will have a lot more room for arguments to avoid a favorable decision for the plaintiff.

Does it Help to Have a Lot of Patent Claims?

A lot of patent claims generally do not help, except maybe during prosecution. In this section, I will look into three different stages in the lifecycle of a patent: prosecution, validity challenges, and enforcement. I looked at over 13,000 opposition cases and will present the first findings from this analysis.

In my opinion, the only stage where a lot of patent claims may help is the prosecution. The European Patent Office sometimes objects to a certain combination of features in claims that are supposedly not clearly and unambiguously disclosed in the application as a combination. Due to multiple dependencies in claims, you could just draft claims for all possible features and then have the perfect ground for combining any feature with any other feature. However, as you see later, a lot of claims can also have drawbacks.


Let’s look at the opposition stage. I have looked at over 13,000 random opposition cases at the EPO and analyzed them with regard to many parameters, such as the number of claims, length of claims, country of the representative, priority country, and about 100 more parameters. I will talk about other parameters in future videos. As for the number of claims, I found the following:

Oppositions are rejected in 17% of all cases, if the number of claims is 21 or more, whereas the opposition is rejected in 25% of all cases if the number of claims is 2 to 10. On the other hand, the patent is maintained in amended form in 38% of all cases, if the number of claims is 21 or more, whereas the patent is maintained in amended form in 29% of all cases, where the number of claims is 2 to 10.

As you may know from your experience, opponents may allow maintenance in amended form, if their own products would not fall into the scope of the amended claims. Many claims offer more choices to amend the patent in opposition proceedings.


And in litigation? Well, the single most important claims are the independent claims, as they determine the scope of the patent. The dependent claims can also play a role but are sometimes even a hindrance for the patentee since the independent claims are sometimes used to interpret the independent claims. In my personal view, a valid patent with only a small number of claims is the best.

Patent Prosecution History Estoppel

In this section, I explain

  • What is prosecution history estoppel?
  • What was the case law until June 2016?
  • What is the new case law in Germany?

Wikipedia has a very concise and nice definition of prosecution history estoppel. Prosecution history estoppel, also known as file-wrapper estoppel, is a term used to indicate that a person who has filed a patent application, and then makes narrowing amendments to the application to accommodate the patent law, may be precluded from invoking the doctrine of equivalents to broaden the scope of their claims to cover subject matter ceded by the amendments. That means that if an applicant has limited the claims from fastening means to screws in prosecution, the applicant will not be able to invoke the doctrine of equivalents to also cover nails. This seems to be the current position in the US.

So what was the case law in Germany until June 2016? In 2002 the Federal Court of Justice in Germany issued a decision called Kunststoffrohrteil (X ZR 43/01). It said that anything before the grant cannot be used to determine the scope of the claims during litigation.

The New Situation Since 2016

In June 2016 the Federal Court of Justice in Germany took a slightly different approach (Pemetrexed, X ZR 29/15). The court held that under the doctrine of equivalents, the claim cannot cover alternatives to a feature in the claim if those alternatives are mentioned in the specification but not included in the claim. In this particular case, the applicant had limited the broader term “antifolate” to the specific compound disodium pemetrexed. The examiner considered that the broader term was not supported by the examples. It could not be generalized to the specific amounts.

So be careful when drafting patent applications for Germany or Europe.  Offer a variety of more specific alternatives as a replacement for broader terms. Also, try to keep this decision in mind when prosecuting your patent application in Germany or Europe.

Tailormade Scope of Patent Claims for Patent Litigation

Wouldn’t it be great to have an individually tailored scope of patent claims for each single patent enforcement against competitors? In Germany, this is not impossible. This is how it is done:

This strategy only works for product claims within the first 10 years of the lifecycle of a patent. You file a German patent application with a very broad first claim. Also, you want as many different features in the claims and description as possible. Then, do not request an examination until the latest possible date 7 years after filing. Then you keep the patent application pending as long as you can without being granted or rejected.

In Germany, you can derive a utility model from any product claim of a pending German patent application. If you see a competitor copy your technology in their own products, you make a test purchase of the product. Then see, what exact features of your claims are infringed. Then, you derive a utility model with claim 1 including all disclosed features that you identified that are infringed. This claim covers the infringing product but is very narrow. Therefore, it will be very difficult for the infringer to invalidate such a claim with the prior art.


The world of patent litigation is undergoing a transformation. Germany, with its rich legal tradition, continues to be a beacon for patent holders. However, the UPC’s introduction necessitates a recalibrated approach, demanding stakeholders to be agile and informed.

I hope that this comprehensive article gave you a good overview of patent infringement proceedings and patent litigation in Germany. If you have any more specific needs, feel free to contact me at any time via email.

Some of the videos have been recorded while I was a partner with my previous patent law firm. Also, note that this article is not legal advice. Please consult us in case you need help.

I wish you success in whatever you do!


Rolf Claessen

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