Accused of infringing an Intellectual Property right. What do I do now?

Suddenly there is a letter on the mat, probably on the letterhead of a law firm, summoning you to immediately stop producing/selling/offering a certain product or service. Because someone else’s trademark/model/patent/copyright/etc. is being infringed.

Those who receive such a letter for the first time may (understandably) panic. For what is to be done now?

Step 1. Contact the right specialist

There are various IP rights, each with its own specialists. For alleged infringement of a trademark or design it is best to contact a trademark and design attorney. For alleged infringement of a patent, you should contact a patent attorney. IP lawyers can help you with other IP matters, such as copyright issues.

It may also happen that infringement of various types of IP rights is alleged. Then a multidisciplinary team is required. In such cases you will benefit from consulting a full-service provider.

Step 2: Is the right valid? And for how long will it remain so?

It is good to start at the beginning. This means first of all checking whether the rights invoked against you are still valid, and if so, where and for how long. Without a valid right, there is no infringement.

Some IP rights, in particular patents and designs, have a limited duration. If it turns out that the patent or design invoked against you will only remain valid for a few more months, it may be a strategic consideration to temporarily stop the sale instead of engaging in battle. This applies even if you are clearly not infringing.

It also never hurts to check whose name the rights are registered in, and whether you have been written to by the rightful claimant (or their representative).

In most cases, these checks will yield little. Nevertheless, it is unwise to skip them. The information you need is publically available,and you can look it up yourself. However, a specialist can help you interpret what has been found and advise you on the possibilities.

Step 3: Are you indeed infringing?

If all goes well, the letter will argue (at least in part) why an IP right is considered infringed. In the case of patents, this can be done by a comparison between the claims of the patent and publicly available information about your product or service. In the case of a design, this usually takes the form of a comparison between the drawings of the design registration and photographs of your product.

However, this does not mean that there is always actual infringement. IP specialists can make their own analysis of how strong the arguments are and, based on that, estimate how great the risk is that you are indeed infringing. Based on this, all kinds of follow-up actions are possible, such as: sending a response letter, in which crucial differences are pointed out and it is argued why there is no infringement at all; submitting a protective letter (“grijsmakingsverzoek”) with the Dutch court in the Hague to try to prevent seizure or other actions; and/or modifying your product to further differentiate it from the right invoked.

Step 4: Has the right been validly granted?

There is another possible defence, even in cases where infringement may be difficult to refute. After all, only validly granted rights can be infringed.

This may be particularly relevant for patents, as the Netherlands has a registration system under which Dutch patent applications are granted automatically. If the patent invoked is such a Dutch patent (as opposed to a European patent validated in the Netherlands), it is advisable to have a patent attorney take a look at the novelty report published with the application. This can provide an initial assessment of the validity at limited cost.

Regardless of the type of patent, a more in-depth validity search can also be carried out, for example searching for documents which were not previously cited but may be relevant to the validity of the patent. Other possible weaknesses are then also examined.

A validity analysis is also often worthwhile for infringement of trademarks and designs. These IP rights, too, must meet certain conditions and may therefore be voidable.

Based on the results of such an investigation, various follow-up actions are also possible here. Proactively claiming the nullity of the right invoked against you is an option. However, it can also be valuable information to enter into a negotiation, or to have in your pocket in case litigation is eventually started.


Nobody wants to be accused of infringing on an IP right. But as the above hopefully makes clear, there is no reason to panic if it should happen. Have you received a summons letter? If so, please feel free to contact our specialists to draw up a plan of action.

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