Preliminary injunction: what the other side does
When a patentee applies for a preliminary injunction, the other side does not simply wait for the court's decision. It challenges standing, disputes urgency, attacks validity of the patent, and asks to be heard before any order takes effect. Each move is aimed at delaying the injunction or narrowing what it covers. The window to act is short, often measured in days rather than weeks.
What changes the moment the application is filed
Once the claimant files, the clock starts running for the other side as well. Depending on the forum, the application may be served immediately or the court may first decide whether to hear the matter without notice. If notice is given, the other side gains a real chance to respond before any restriction is imposed. If the application is heard without notice, the first opportunity to be heard often comes only after an order is already in place.
This distinction matters more than most other details in the file. An order granted without notice can be reversed on reconsideration, but reversing it costs time, and time is exactly what the claimant was trying to buy.
Steps the other side typically takes
- Instruct counsel without delay. The response window is short and missing it can mean losing the chance to be heard before the order is issued.
- Request the full case file, including any confidential annex, so the scope of the alleged infringement is clear before drafting a response.
- Prepare a substantive objection addressing both infringement and the validity of the patent relied on. A validity challenge, even a preliminary one, changes how the court weighs urgency.
- Ask for security from the claimant, so that if the injunction later turns out to be unjustified, there is a fund to cover the loss it caused.
- Request an oral hearing rather than a decision made only on the papers. A hearing gives the other side a chance to test the claimant's evidence directly.
- Preserve evidence of the challenged activity before any restraining order takes effect, including records of the underlying technical files. Where those files sit with an external design agency rather than in-house, retrieving them on short notice raises its own timing questions — see When an agency keeps the design files in detail.
Where the patent portfolio at issue also includes a tokenised licensing right, the documentary record for that asset follows a different checklist entirely, and preparing it early avoids a second scramble once the injunction hearing is fixed — see Mapping a right to a token in detail.
Where evidence gathering touches personal data — call logs, access records, correspondence between staff — the basis for processing that data is often covered in Legitimate interest assessment explained. It is worth checking before documents are compiled, not after.
Who decides, and how fast
The court seised of the infringement claim decides the injunction request, usually the same judge or panel handling the underlying case. Speed depends on three things: whether the claimant asked for a decision without notice, whether the other side requests a hearing, and how the court's own calendar runs that quarter.
| Stage | Typical actor | Typical timing |
|---|---|---|
| Application filed | Claimant | Immediate, sets the clock running |
| Notice to the other side (if given) | Court or registry | Same day to a few days |
| Written response or objection | Other side | Short, often within one working week |
| Hearing, if requested | Court | Weeks, depending on the calendar |
| Decision issued | Court | Shortly after the hearing closes |
| Reconsideration or appeal window opens | Other side | Short, set by the forum's own rules |
If the situation differs
If the injunction was granted without notice, the other side's first and most urgent move is to request a rapid hearing to reconsider it, not to file a full defence on the merits straight away.
If a separate revocation action against the patent is already pending, the other side raises that pending challenge as a reason to suspend or narrow the injunction rather than lift it outright.
If the other side does not respond at all within the window given, the court is likely to decide on the claimant's submissions alone, and the resulting order becomes far harder to unwind afterwards.
What this page does not cover
This page describes the sequence of moves and who typically makes them. It does not set out the exact days allowed in any one jurisdiction, the wording of a specific objection, or how a court will weigh a particular set of facts — those depend on the forum seised of the case and on the file itself.
It also does not cover checks on the other side's own standing to litigate, which sometimes matter as much as the injunction itself. Where the other side is incorporated outside the EU, verifying its corporate standing is a separate exercise — see Counterparty in Hong Kong in practice for one example of how that check runs.
Verified
Reviewed and current as of this publication. The sequence described reflects common procedural practice across the courts that hear patent injunction requests; it is not tied to a single statutory source, and the exact deadlines depend on the rules of the forum seised of the case.
Related reading
The injunction stage is usually the opening move, not the whole case. What follows if the claim proceeds to a full hearing is set out separately — see Main infringement action step by step.
Frequently asked questions
How long does preliminary injunction take in practice?
It depends on whether the claimant asked for a decision without notice and whether the other side requests a hearing. An unopposed, urgent request can be decided in days; a contested request with a hearing usually takes longer, running into weeks.
Which documents are needed to start?
The other side needs a written objection, evidence disputing infringement or validity, documents proving its own standing to respond, and, where relevant, prior art or a non-infringement analysis prepared in advance.
What happens if the other side does not respond?
The court is likely to decide on the claimant's material alone. The resulting order still takes effect and can be enforced; contesting it afterwards through reconsideration or appeal is possible but starts from a weaker position.