Get in touch


Thank you

What are oppositions?


First off, what exactly are oppositions? Simply put, once the European Patents Office (EPO) has granted you or a competitor a patent, there is a nine-month window to file a complaint and argue the patent was incorrectly granted. Keeping track of the latest patents is particularly useful since your competitors will likely have patents that limit your freedom to use specific features in your products or services. The EPO may grant a patent, but it may not necessarily be valid if there are earlier disclosures of the same invention or something very similar. Filing an opposition is a public opportunity to check and validate the work of the EPO. By opposing a patent, you can potentially have the decision of the EPO work in your favour.


Patents are often broad and sometimes their wording needs clarification. This is especially common with new technologies. What is and isn’t covered needs to be correctly interpreted as well as what has already been disclosed in other patents. By opposing a new patent, you can check and show what has already been disclosed and narrow its definition based on your limitations. Then, when you know the exact definition of the patent, you can be confident you have freedom to operate up to a certain point without legal recourse (more on this below).


How oppositions increase your freedom

Freedom to operate means knowing that the technology you’re selling does not infringe any third-party patents. By keeping up with your competitors’ patents you’ll have a sounder understanding of where your limitations lie and what you can and can’t sell (for example, you may need to modify a product before putting it on the market to avoid running into a competitor’s patent). 


It’s a good idea to keep track of your competitors’ patents as well as the nine-month windows to file oppositions. This way, you’re less likely to be unexpectedly confronted with a patent that conflicts with one of your products or services down the line. 


The positive outcomes you can expect from an opposition

Oppositions centre on shielding your original work against competitor patents and making sure that a competitor patent does not protect more than it deserves. Oppositions can narrow or even revoke a patent, giving you greater or total freedom to operate, or they can lead to cross-party discussions if there’s potentially a mutual benefit.

The positive outcomes you can expect from an opposition are:


  • Revocation. This is the ideal outcome. The EPO decides to invalidate a patent based on your opposition, giving you maximum freedom to operate.
  • Limitation or amendment. A patent must be amended and its scope narrowed. This often makes it easier to stay competitive as you can find alternative ways to innovate and sell your products or services.
  • Increased certainty. This may have an effect similar to a limitation. Even if you don’t succeed in revoking or limiting the patent, you now know exactly how the patent is to be interpreted. For instance, before you filed an opposition you may not have known whether you’d be successful in arguing that you don’t infringe a patent in court. But, with a clear decision of the patent office about how to interpret the patent claims, you obtain increased certainty. You then know how broad or narrow the competitor’s patent is and how you can operate as a result.
  • Opening a cross-licensing discussion. If you’re in a highly competitive market, and one of your competitors is innovating similarly to you, sometimes it can be more beneficial to open the door to licensing discussions. For instance, if you have valid arguments against a competitor’s patent, you may not even need to file your opposition. Instead, you can reach an agreement with the other company, where they licence you to use their patent either for a fee or for free in exchange for one of your patents, or just for your promise not to invalidate their patent in an opposition procedure. You may allow your competitor to use one of your patented features in return for one of theirs, for instance.  Furthermore, you’re only licensing one other company to use your IP (intellectual property) and vice versa, meaning your patent can still be held against the rest of the market. In this way, agreeing to cross-licensing can give you and the other company a competitive advantage.


Opposition timelines and potential costs of alternative routes

Once the EPO grants a patent it’s valid in 25 European countries and you have nine months to file an opposition. The official filing fee is £815 and the cost of preparing and submitting ranges from £3,000-10,000. The total cost for the complete process typically ranges from £15,000 to £30,000, though it may be more for a high-stakes case. Once filed, the EPO will decide on the validity of the patent in 18-24 months and this involves further opportunities for exchanging arguments in writing and a final hearing.


It’s very important to keep track of new patents and be aware of the timeframes for submitting oppositions. If you miss the deadline, it may still be possible to invalidate the patent but this must be done individually in each relevant EPO member state, which will greatly add to the costs.


It’s very important to consider the costs of alternative legal routes and potential patent infringements when you’re weighing up the costs of submitting an opposition. If you’re being sued for infringement, full court costs in some countries can run to hundreds of thousands as you prepare a defence and develop counter-arguments to defend your product against the patent. Furthermore, you may have to stop selling your product altogether, possibly temporarily during the course of the infringement procedure, or permanently if you’re unsuccessful in court.


How to develop an opposition strategy

Getting an opposition strategy started all begins with monitoring your competitors and keeping an eye on the latest applications they’ve filed and which of those are granted. If your competitors take their IP seriously and regularly submit patents, it’s doubly important for you to check whether their newly granted patents protect specific features that your product or service uses, or that you’re currently in the process of developing.


It’s better to be actively opposing competitors’ patents rather than operating in the dark and risking infringement on another company’s IP. One way to do this is to inspect the patents of other companies and decide whether you can take action against them to narrow their scope and increase your freedom to operate. For instance, you can periodically check what patents that company holds and then, in turn, oppose them, if you have grounds to do so. This way, you can potentially invalidate the patent before the company has the chance to act against you.


Monitoring a competitors’ patent portfolio also gives you valuable information about what they are working on. With a sound patent monitoring and opposition strategy, you can see ahead of the curve and gain a sense of the general direction your industry is heading in. If you spot any features in patents that you may be planning to use in your products, you can act against those patents swiftly and have them narrowed or revoked to maintain your freedom to operate and stay competitive. 


Read more about how Keltie can help protect your inventions, brand, and designs and help you maintain your competitive advantage in your market. Contact us at one of our UK and Ireland offices to discuss with one of our IP attorneys how to develop an opposition strategy and file oppositions at the EPO.

Continue reading about Why It’s Important to File Oppositions at the EPO to Increase Your Freedom to Operate
MoreQ&A with Michael Moore: Leading innovations in biotechnology and intellectual property


Q&A with Michael Moore: Leading innovations in biotechnology and intellectual property

Keltie features again in the Financial Times' prestigious list of Europe's Leading Patent Law Firms 2024. Keltie is one of the leading firms of IP specialists in Europe and is recognised by its peers across several core areas. We talk to Mike to discover what makes a successful IP firm and how biotechnology is evolving. He discusses his journey into the field and talks about all things ‘AI’.

MoreUPC Court of Appeal reverses Preliminary Injunction in first substantive decision


UPC Court of Appeal reverses Preliminary Injunction in first substantive decision

The Court of Appeal of the Unified Patent Court (UPC) recently published its first decision considering substantive issues, in which it overturned a first instance decision of the Munich local division (NanoString (appellants) v 10x Genomics (respondents), UPC_CoA_335/2023).

Get in touch


Thank you