Patent Litigation in France: Complete 2026 Guide

If you have a patent dispute touching France, one fact decides almost everything about how it will run: there is only one court. Every French patent case, wherever the parties sit, is funnelled to a single specialised division in Paris. Patent litigation in France is heard by the Tribunal judiciaire de Paris, which has exclusive national jurisdiction over patents and rules on infringement and validity in the same proceeding – no splitting the case in two. Add the arrival of the Unified Patent Court, whose Central Division has a seat in Paris, and France now offers two overlapping forums. This guide explains who hears what, the evidence tools that make France distinctive, and what a case realistically costs and takes.

How Patent Litigation in France Works

Patent litigation in France is centralised by law in the Tribunal judiciaire de Paris – the Paris Judicial Court – and specifically in its specialised intellectual property chamber. Since a 2009 reform, that court holds exclusive national jurisdiction over French patents, so it does not matter where the defendant is based or where the infringement happened: the case is heard in Paris by judges who do patent work full time.

Cases on the merits are decided by a panel of three judges, while urgent applications – preliminary injunctions and ex parte requests – go before a single judge. The Institut national de la propriete industrielle (INPI) grants French patents and handles some administrative proceedings, but it does not hear infringement suits. Enforcement is a court matter from the start, and the parties are represented by specialist patent litigators before a bench that sees these cases every week.

One Court, One Case: Non-Bifurcation

France is a non-bifurcated system, and that word carries real strategic weight. When a patent owner sues for infringement, the defendant almost always attacks the patent’s validity as a counterclaim – and the same Paris court decides both questions together, in one judgment. There is no separate validity forum and no waiting.

This is the opposite of Germany, where infringement and validity are split between different courts on different timetables – the so-called injunction gap. Because a French judge weighs infringement and validity side by side, a strong invalidity case can neutralise an infringement claim in the very same proceeding. For anyone defending, that makes an early, rigorous invalidity analysis the single highest-value move. Our guide to patent litigation in Germany shows just how differently the bifurcated model plays out.

The practical consequences of hearing everything in one place are worth spelling out:

• No injunction gap – a defendant cannot be enjoined on an infringement finding while the validity attack is still pending elsewhere, because both are decided together.
• Validity is a live defence, not a separate campaign – the prior art you assemble goes straight into the same case rather than a parallel revocation action.
• One judgment, one appeal – infringement and validity rise or fall together, which makes the outcome easier to predict and settlement easier to price.
• Preparation front-loads – both sides must have their technical and invalidity evidence ready earlier than in a bifurcated system.

Saisie-Contrefacon: France’s Evidence Weapon

The tool that makes France a patentee-friendly venue is the saisie-contrefacon – an infringement seizure. On an ex parte application, the Paris court can authorise a bailiff, often accompanied by an independent technical expert, to enter the alleged infringer’s premises and seize samples, documents and detailed evidence of the infringing activity, all before the defendant knows a case is coming.

For a patent owner who suspects infringement but cannot prove it from the outside, the saisie is transformative: it captures the evidence you would otherwise never obtain. But it is tightly regulated. You must launch the infringement action within a short deadline after the seizure or the saisie is void, and an abusive or disproportionate seizure can be annulled and expose you to damages. Handled well, it is the strongest opening move in French patent practice.

The UPC and the Paris Central Division

Since 1 June 2023, France has been a founding member of the Unified Patent Court, which runs in parallel with the national court. The UPC has exclusive jurisdiction over unitary patents and, unless they have been opted out, over classical European patents validated in France. Its Central Division has one of its three seats in Paris, handling revocation and certain infringement actions in technical fields including physics, electricity and mechanical engineering.

That creates a genuine fork in strategy. A classical European patent validated in France can be litigated either at the Tribunal judiciaire de Paris or at the UPC – but only until the patent holder decides whether to opt out of the UPC during the transitional period. A unitary patent has no such choice; it lives or dies at the UPC across all participating states. If your right came through the European route, our guide to validating a European patent in France explains the upstream decisions that set up this fork.

Remedies, Timeline and Costs

A French court that finds infringement can order a permanent injunction, award damages, and require recall or destruction of infringing goods. Before trial, a patent owner can seek a preliminary injunction in urgent proceedings, though the court will refuse it if the patent’s validity is seriously in doubt. The limitation period for bringing an infringement claim is five years.

In practice, a first-instance case on the merits commonly runs about eighteen to twenty-four months, and costs are modest compared with US litigation because there is no broad discovery – the saisie does that work instead. Appeals go to the Paris Court of Appeal, and points of law can reach the Cour de cassation. Budget for expert evidence: technical complexity, not procedural volume, is what drives French patent costs.

Damages in France are compensatory rather than punitive. The court looks at the patent owner’s lost profits, the infringer’s gains, and a reasonable royalty, and it can order the losing side to contribute to the winner’s legal costs. That cost-shifting, combined with the modest overall spend, means a well-founded French case can be economically rational even for a mid-sized business – provided the invalidity risk has been honestly assessed before the first filing. The forum’s efficiency cuts both ways: a weak patent is exposed just as quickly as a strong one is enforced.

Where French Litigation Fits Your Strategy

France rewards preparation. For a patent owner, the combination of a specialised Paris court, the saisie-contrefacon and a single non-bifurcated proceeding makes it an efficient place to enforce. For a defendant, the same features mean an invalidity case must be ready early, because validity is decided alongside infringement rather than years later in a separate forum.

That is where the pre-litigation work pays off. Our teams supporting clients in Paris and Lyon, and across the France services hub, build the invalidity and prior-art record that decides these cases. For a neighbouring European comparison, see how the forum choice differs in patent litigation in Switzerland.

Prepare Your French Patent Case With Confidence

Whether you are enforcing a patent in Paris or defending against an infringement claim, the case is won on the evidence and the invalidity analysis you prepare before filing. PerspireIP’s prior-art and invalidity searches give French patent litigation its backbone. Contact our team to build your record.

Frequently Asked Questions