French saisie-contrefaçon or UPC evidence preservation: the decision matrix
A patentee facing suspected infringement in Europe now has two evidence-gathering instruments: the French saisie-contrefaçon, granted ex parte, and evidence preservation before the Unified Patent Court. They are not interchangeable. The choice is made before the first formal step, and it is difficult to undo.
The short answer: the French infringement seizure (saisie-contrefaçon) remains the broader and safer instrument where the evidence must be used outside Europe, where the applicant’s usual patent attorney needs to attend the operations, or where France is the principal territory of infringement; a preservation measure before the Unified Patent Court Unified Patent Court (UPC) is the right choice where the action on the merits will be brought there. What follows explains why, and what each route requires you to prepare.
What the French seizure still offers
The actual seizure for infringement remains the widest evidence-gathering measure in European patent litigation. It is granted on an ex parte application, without notice, and the element of surprise is complete. The commissaire de justice may describe, sample and seize, and the scope of the order can extend to accounting records — often the real object of the exercise, well beyond establishing that infringement occurred.
Two features set it apart from what the Unified Patent Court offers. The first is the attendance of the applicant’s usual patent attorney, who knows the patent and knows what to look for. The second is that evidence obtained in France can be deployed in foreign proceedings, which makes the measure an entry point for worldwide disputes rather than a purely domestic step.
Two constraints have changed how operations are run
Proportionality
Under the influence of EU law, the judge now assesses the proportionality of the measure and expects reasonable evidence of infringement. The threshold is low, and in practice the requirement bears on the scope of the measures authorised far more than on whether the order is granted at all. The operational consequence is direct: it is the drafting of the application, not any hearing, that determines what the applicant will actually be able to take away.
Sequestration and trade secrets
Since Law No. 2018-670 of 30 July 2018 and Decree No. 2018-1126 of 11 December 2018, the party seized has a structured mechanism for protecting its trade secrets. Material taken is placed under provisional sequestration, and Article R. 153-1, paragraph 2, of the French Commercial Code opens a one-month period running from service of the decision , not from the seizure itself — in which to seek amendment or setting aside of the order and to oppose the automatic release of the sequestered material.
That distinction is frequently misstated and matters a great deal in practice. The French Supreme Court has also held, on the combined basis of Article R. 615-2 of the Intellectual Property Code and Article R. 153-1 of the Commercial Code, that provisional sequestration is not optional.
The consequence is that the sequestration phase, long treated as a formality, in fact decides what the claimant will put before the court. A flawlessly executed seizure whose sequestration is poorly defended is worth nothing.
What a UPC measure changes
The Unified Patent Court has its own instruments for preserving evidence. Their attraction is obvious where the action on the merits will be brought before it: the evidence is gathered within the procedural framework that will judge it, and its admissibility is not open to argument.
But the logic differs on one decisive point. The French procedure is entirely ex parte ; before the Unified Patent Court, an inter partes discussion is structurally available and the judge may invite one. The applicant may then withdraw the application, but surprise is lost. That is not a difference of degree — it changes the nature of the tool.
There is also a forum consideration. The divisions do not share the same familiarity with so intrusive a procedure, and French experience of it is long-standing. Bringing a preservation application before judges accustomed to the exercise is not a matter of comfort: it is a parameter of the outcome.
Choosing: the matrix
| Situation | Instrument | Decisive reason |
|---|---|---|
| The evidence must serve proceedings outside Europe | French seizure | Reach of the evidence and security of its use abroad |
| France is the principal territory of infringement | French seizure | Exclusive jurisdiction of the Paris Judicial Court |
| Attendance of the usual patent attorney is decisive | French seizure | Technical reading of the patent during operations |
| Surprise is essential | French seizure | Entirely ex parte procedure |
| The action on the merits will be brought before the UPC | UPC measure | Procedural continuity and admissibility |
| Infringement is spread across several participating States | UPC measure | Territorial reach of the measure |
The two routes are not mutually exclusive. A French seizure can prepare an action before the Unified Patent Court, and combining the instruments is legitimate where the geography of the infringement calls for it. What is excluded is deciding after the event.
Preparing — on both sides
If you are considering acting. Assemble the reasonable evidence of infringement before drafting the application. Settle the scope: premises, categories of document, IT systems, individuals. Choose the commissaire de justice and the expert. Fix the timetable for the action on the merits, on which the validity of the seizure depends. Decide the forum first, not afterwards.
If you may be on the receiving end. Identify in advance what constitutes your trade secrets and where they sit. Designate a single point of contact for the day. Note that the one-month period under Article R. 153-1 of the Commercial Code is short and cannot be recovered. Unpreparedness on the part of the party seized is, in practice, the single largest contributor to the applicant’s success.
Key takeaways
- The French seizure remains broader than a UPC preservation measure, and is entirely ex parte.
- Proportionality
- The one-month period under Article R. 153-1, paragraph 2, of the Commercial Code runs from service of the decision, not from the operations.
- Sequestration decides what is actually produced at trial.
- Before the Unified Patent Court, an inter partes discussion is possible: surprise is not guaranteed.
- The choice of evidentiary forum is difficult to reverse and is made before the first formal step.
Frequently asked questions
Must infringement be proved to obtain a saisie-contrefaçon?
No. The applicant must establish its title and standing and present reasonable evidence of infringement. The proportionality requirement bears on the scope of the measures authorised, not on the grant of the order.
What happens if proceedings on the merits are not brought in time?
The seizure is void and the evidence obtained is lost. The period is calculated from the day of the operations and is not negotiable.
trade secrets
from service of the decision
Can a French seizure support subsequent UPC proceedings?
Nothing prevents it, and that articulation is prepared from the application stage onwards. It presupposes that the forum for the action on the merits has already been settled.
Anticipate rather than react
Evidentiary forum, scope of the order and the timetable for the action on the merits form a single set of decisions, taken together and before the first formal step. Dhenne Avocats prepares and conducts these measures for applicants, and challenges them for respondents, before the Paris Judicial Court and the Unified Patent Court. Discuss a matter.
This article is an original and substantially updated adaptation of an analysis by Matthieu Dhenne first published on Kluwer Patent Blog.