What is Patent Infringement?

Discover the consequences of patent infringement for companies and individuals.

Update: Aug 11, 2026

Siert Bruins

Understanding patent infringement is important for every inventor and entrepreneur. Whether you have recently obtained a patent or are developing a new product, it is essential to understand both how your own patent rights can be enforced and how to avoid infringing patents owned by others. Patent law protects exclusive rights, but those rights are not enforced automatically. The responsibility for detecting infringement and deciding whether legal action is appropriate lies with the patent holder.

So, if you're an inventor or developing technology with your business, you may:

1. Encounter infringement on your patent if another party duplicates your technology or product and markets and sells it.
2. Infringe on someone else's patent. It's not just a concern for patent holders; even if you develop and market a product, you must ensure you aren't infringing on another party's patent. This aspect is often overlooked and can lead to unpleasant surprises. On the page about "does my idea already exist?", you'll learn how to search if there's already an existing patent describing your idea.

Infringement only occurs when commercial intentions are involved. This means that businesses, in particular, must be cautious about what they introduce and produce in the market.

For clarity: not everyone can infringe on a patent. As a consumer, you're unable to commit infringement. Universities and research institutions also do not violate Intellectual Property Rights when conducting scientific research. Additionally, infringement only applies in countries where the patent is valid. Therefore, if an ingenious invention is patented only in the Netherlands and Belgium, you're free to introduce the same product as a competitor to the patent holder in the USA and other countries. However, permission is required in the Netherlands and Belgium, obtained through a written agreement such as a license. The license agreement determines, among other things, the amount of licensing fees to be paid to the patent holder.

In case of patent infringement, the patent owner can demand the immediate withdrawal of the product from the market and may also claim compensation, the amount of which is determined by the court. The infringer is also responsible for the legal costs of the opposing party. However, a patent holder might be content if the patented product is immediately removed from the market without the need for legal action.

So, after obtaining a patent, your work is not done; the real work begins. As a patent holder, you're responsible for monitoring the market for potential patent infringement. But how do you do that?

Three ways to monitor potential infringement on your patent

Firstly, it's essential to monitor your competitors' activities. Track their presentations on websites, in brochures, and in advertisements. Regularly check industry magazines and visit their websites and social media monthly; these are often critical sources to verify potential patent infringement.

A second method is leveraging the knowledge of the individuals selling your products. They understand the market best because they attend trade shows, engage extensively with current and potential customers, and quickly discover any potential infringement on your patent. For example, they might hear, "Your competitor is selling a device that does the exact same thing, but for much less." Yeah, sure, that's logical; you then think, perhaps your competitor had much lower development costs (since they copied your idea), and they certainly don't have an expensive patent to maintain...

A third and final suggestion is not only to monitor the market but also to check patent databases for any patents similar to yours. Ideally, these applications shouldn't be granted, but you never know. After all, you're the one who precisely knows how your technology works, and perhaps the reviewer or the competitor's patent agent didn't quite understand it. You can collaborate with your patent agent to set up a system that searches patent databases for publications similar to your patent. Youw will receive an overview of potential infringers on a regular basis. Discuss with your patent agent which monitoring method best suits your situation. If you can't or don't want to bear these costs, it's also possible to periodically search public patent databases yourself using a set of keywords you've compiled.

If you identify potential infringement of your patent by a competitor, it is essential to gather solid evidence before taking any action. This includes documenting when and where the infringing product or service was observed, collecting screenshots or product photos, saving web pages, and purchasing or testing the product if possible. Carefully preserving this evidence is essential in case legal steps become necessary. Before sending angry emails or making accusatory phone calls, consult your local patent attorney. They are experts in intellectual property law and can advise you on the most effective and strategic course of action.

In many infringement disputes, the accused party will try to show that the patent should never have been granted in the first place. One common argument is that relevant prior art already existed before the patent was filed, which can invalidate the patent entirely. They just try it....

Patent disputes between companies can escalate quickly, turning into lengthy and expensive legal battles. These conflicts may take years to resolve and often require substantial financial and legal resources, especially when the stakes involve breakthrough technology or large market potential. A striking example is the ongoing patent dispute between the giants Apple and medical device company Masimo. Their battle over smartwatch technology used to measure blood oxygen levels illustrates how serious, complex and very expensive such cases can become. Read more about this high-profile patent case between Apple and Masimo.

A Patent Can Also Protect Individual Inventors

Patent disputes are often associated with large multinational companies defending valuable technologies, but the patent system is equally important for individual inventors. A well-drafted patent gives its owner the same legal rights, regardless of whether the patent belongs to a global corporation or a single inventor. Enforcing those rights may be challenging, but a strong patent can withstand legal scrutiny when it is based on a genuinely novel and inventive idea.

An excellent example is the famous patent on the notch in a rusk. Inventor Theo Tempels successfully defended his patent against challenges brought by several large companies that argued the invention lacked inventiveness. The courts repeatedly upheld the validity of the patent, demonstrating that individual inventors can successfully enforce their rights against much larger competitors when their patent is legally sound. Read the full story in our case study on the patent on the notch in a rusk.

Disputes like the one between Apple and Masimo are more than potential patent infringement—they're part of a broader legal process known as IP litigation. When two parties can't settle an intellectual property conflict informally, the case may move to court, a process that can be lengthy, complex, and costly. Read more about IP litigation here.

Related Questions

• How can I avoid infringing other patents?
  Learn practical strategies to reduce the risk of infringing existing patents before bringing a new product to market.
• What is IP Litigation?
  Discover what happens when patent disputes cannot be resolved through negotiation and proceed to formal legal action.
• What is Prior Art?
  Understand how earlier publications and existing inventions influence patent validity and why prior art is central to every patent strategy.
• Can a patent be declared invalid?
  Learn how granted patents can still be challenged and under which circumstances a court or patent office may invalidate them.

Understanding patent infringement is an important part of deciding how to protect and commercialise your invention. If you want to see how intellectual property, validation, development, financing and other decisions fit together, follow the Build to Sell roadmap.