Preliminary injunction: stages and deadlines
A preliminary injunction stops alleged infringement before the main patent case is decided. It moves fast: a court weighs urgency, the strength of the infringement claim, and the harm an injunction would cause the other side, often within days rather than months. Miss the point at which you knew about the infringement, and the same court can refuse the request on that ground alone.
Why timing decides the outcome
A preliminary injunction is not a smaller version of the main claim. It is a separate, faster procedure built around one question: can the situation wait for a full trial? A court will not grant urgent relief simply because the patent looks strong on paper.
Urgency is judged from the moment you became aware of the infringement, not from the moment you file. A gap between discovery and filing — spent gathering more evidence, negotiating, or simply deciding what to do — can be read as proof that the matter was never urgent. Once a court reaches that conclusion, the request usually fails regardless of how clear the infringement itself turns out to be.
Alongside urgency, the court weighs the harm an injunction would cause the other side against the harm of doing nothing. A request that would shut down an unrelated part of the defendant's business faces closer scrutiny than one aimed narrowly at the disputed product.
Stages, in order
The sequence below holds across most patent disputes in the EU. The exact calendar length depends on the forum, on how contested the facts are, and on whether the other side is heard before the decision is made.
| Stage | What happens | What starts the clock |
|---|---|---|
| Evidence gathering | Proof of the patent, proof of the infringing act, and proof of urgency are assembled before anything is filed. | The moment infringement is discovered |
| Filing the request | A written application sets out the patent, the alleged infringement, and why the matter cannot wait for a full trial. | Submission to the competent court |
| Initial review | The court checks urgency and the strength of the claim. In genuinely urgent cases, it can decide without hearing the other side first. | Immediately after filing |
| Security | The court can require the applicant to lodge security, to cover the other side's loss if the injunction later turns out unjustified. | Set together with the decision |
| Notice and hearing | Where the case is not treated as an emergency, the other side gets a short window to respond before a decision is made. | After the initial review |
| Decision and service | The injunction takes effect once served. Continuing the disputed activity after that point becomes a fresh, separate breach. | From service of the decision |
| Link to the main case | Where the injunction was granted without a full hearing, the applicant is normally expected to pursue the main infringement claim to keep it in place. | After the injunction is granted |
What to do before filing
- Fix the date you learned of the infringement. Write it down with supporting evidence — an internal note, a screenshot, an email thread. This date drives the entire urgency argument.
- Collect proof of the infringing act itself. Counsel or an in-house IP manager should secure product samples, listings, or technical documentation before they can disappear.
- Confirm ownership and standing. Check the patent register entry names the applicant as owner or exclusive licensee. Gaps here stop a request before it starts.
- Decide on the emergency route. A litigator assesses whether notifying the other side in advance would let it destroy evidence or accelerate the harm.
- Prepare for security. Set aside funds or line up a bank guarantee that the court may require as a condition for granting the injunction.
- Line up the main action. Draft the substantive infringement claim in parallel, so it can follow immediately once the injunction is granted.
Who decides, and how fast
The competent forum depends on the type of patent. A request concerning a unitary patent goes to the Unified Patent Court. A request concerning a national patent goes to the national court that handles patent matters in the country where the infringement occurs.
Speed is the point of the procedure. A genuinely urgent request is assessed in days, not weeks. The court can rule without a hearing where waiting for the other side to respond would itself cause the harm the injunction is meant to prevent. A request that is not clearly urgent moves at the pace of ordinary interim proceedings — still faster than the main action, but no longer measured in days.
Both sides usually retain a route to challenge the outcome: the losing party can ask the same court to reconsider, or take the matter to a higher instance. That review runs on its own timetable and does not automatically pause the injunction while it is pending.
Two situations that change the route
If ownership of the invention itself is disputed — for example, where an agency produced AI-assisted design work under a services contract — that question needs resolving before an injunction request can stand: AI products and models an agency keeps the design. A court will not grant urgent relief to an applicant whose title to the patent is itself in question.
If the infringing goods are moving through customs rather than sitting on a shelf, a parallel route exists: a request to intercept goods at the border. It runs on its own application and its own timeline, alongside the injunction request rather than instead of it.
What this page does not cover
This page describes the procedural shape of a request. It does not set the level of security a specific court will demand, the exact number of days a specific forum takes to decide, or the odds that a given patent survives a validity challenge raised in defence. Those depend on the forum, the patent, and the evidence, and each is assessed case by case.
It also does not cover due diligence on the other side before a claim is filed. Where the opposing party sits outside the jurisdiction, a separate check is often the first practical step: Counterparty in Austria in practice.
Verified
Reviewed in the current cycle. No article numbers or regulation citations appear on this page by design: the procedure above is described at the level of stages and forums, not at the level of statutory text, because the national provisions behind it are checked separately for each jurisdiction before they are relied on. For how sources are tiered and delivered across the site, see Sources by tier and delivery route overview step by.
Frequently asked questions
How long does a preliminary injunction take in practice?
A genuinely urgent request can be decided within days. A request that is not treated as urgent moves at the pace of ordinary interim proceedings, which is slower but still faster than a full trial.
Which documents are needed to start?
Proof of ownership of the patent, proof of the infringing act, and a clear, dated account of when the infringement was discovered. The last item supports the urgency argument and is often the weakest part of a rushed application.
What happens if the other side does not respond?
Where the case was heard without the other side present, the decision takes effect on service regardless of any later response. Where the other side was given a chance to respond and stays silent, the court decides on the material the applicant has filed.
Related reading
A preliminary injunction is a step inside the wider dispute, not a substitute for it: Main infringement action step by step sets out what follows once the interim question is settled.
Talk to a partner today
If the underlying dispute could instead be settled by letting two rights coexist rather than fighting for exclusivity, read this first: When a coexistence agreement is proposed: what to do.
If the dispute touches a tokenised or digital asset rather than a physical or software product, the starting point is different: When a fork duplicates the token explained.
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