All questions

Procedure in patent enforcement and invalidity actions

i Competent jurisdictions

The Paris courts have exclusive jurisdiction to hear civil actions relating to patents (which include infringement and invalidity proceedings).

ii General procedural aspects

The burden of proof (in both infringement and nullity actions) rests with the claimant. The claimant's writ of summons must contain detailed arguments in law and in fact, so that the court can form a judgment by itself. A case management judge sets the timeline of the proceedings and it is typical for both sides to file two or three briefs. Once the case is ready to be heard, the instruction is closed, which means that the parties can no longer exchange any brief or exhibit, and a final oral hearing is set. Hearings generally last between three and five hours, depending on the complexity of the case.

Infringement and nullity can be dealt with during the same hearing, as both can be invoked as counterclaims (unless they are time-barred, in which case nullity could be raised only on an exception basis, namely inter partes).

The claims of a patent can be amended during the proceedings, even throughout an appeal.

The total average length of first instance proceedings is between 18 and 24 months. Appeals last for a similar length of time. In cases where urgency is demonstrated within an ex parte request, a summons to appear on a fixed date under special emergency rules can be authorised to obtain a quick judgment on the merits (approximately five to six months). This is rarely sought but has been attempted in the context of the revocation of a patent and a declaration for non-infringement.

Summary proceedings may last between three and five months in first instance (and around six months on appeal).

iii A unique tool: the saisie-contrefaçon

Infringement can be proved by any means; for example, a bailiff's report or a saisie-contrefaçon. Unlike litigation in the United States or the United Kingdom, French proceedings do not include discovery or disclosure and there is no incentive for a party to admit or concede any points (for example, there is no cost consequence). As such, any affirmation must be proven by written evidence.

The saisie-contrefaçon is a very specific and efficient probative measure, which must be carried out with caution. It is performed as a first step in almost all infringement proceedings. It allows any claimant or potential claimant to instruct a bailiff to enter any location and write a detailed description of the alleged infringing product (with or without the taking of samples) or process. The bailiff may also be assisted by experts (for example, patent attorneys) designated by the claimant.

To perform a saisie-contrefaçon, the claimant must obtain an order from the president of the Paris Judicial Court by way of an ex parte request. The order should specify very precisely the scope of the bailiff's mission.

The claimant only needs to prove that he or she is entitled to bring an infringement action (i.e., that he or she is the owner or exclusive licensee) and that the patent is in force (i.e., that annual fees have been duly paid). The Paris Court of Appeal recently recalled that it is not necessary to prove infringement to obtain permission to carry out a saisie-contrefaçon, because the exact purpose of the saisie-contrefaçon is to determine whether an infringement has occurred and to what extent. However, bringing 'reasonably available evidence of infringement' is still required.

Challenging the validity of saisie-contrefaçon has become a 'national sport', which has given rise to a wealth of case law. Alternatives such as bailiff reports can be used, but case law around the validity of such alternatives is very strict.

Both the ex parte request and the order for a saisie-contrefaçon must be notified to the seized party before the commencement of the saisie-contrefaçon.

Once the saisie-contrefaçon has been performed, the requesting party must bring an infringement action on the merits within a month. If it fails to do so, the saisie-contrefaçon can be annulled, without prejudice to any compensatory damages that the seized party may claim for any losses incurred.

The seized party also has the ability to challenge or modify the order or request its withdrawal in summary proceedings. It can also seek a court order to protect the confidentiality of seized material.

To ensure that seized material is kept confidential, 'confidentiality clubs' may be established between the lawyers and patent attorneys of each party, subject to non-disclosure agreements being entered into by the participants.

iv Right of information

The claimant has a right to request any documents and information necessary to determine the origin and distribution networks of the alleged infringing goods or processes. This right can be exercised even if the claimant has not applied for or performed a saisie-contrefaçon.

The Supreme Court has ruled that the right of information could also be used in acquiring documents and information to determine the extent of the infringement and to refine claims for damages.

In practice, this right is generally granted once a judgment ruling on infringement has been rendered and damages are then assessed through further separate proceedings before the same judge based on the information disclosed.

v Standing to sueStanding to initiate an infringement action

Infringement proceedings must be initiated by the owner of a granted patent or patent application. In the latter case, the action will be stayed until the patent is granted.

If the patent is co-owned, each of the co-owners may initiate infringement proceedings for its own benefit but it must inform the other co-owners, unless otherwise provided in the co-ownership agreement.

If the patent has been assigned, the assignee will only be able to act if the assignment agreement has been registered at the IPO and this registration has been published. Further, unless expressly agreed upon between the parties, the assignee cannot claim damages for infringing acts that happened prior to the publication of the assignment. This situation may be regularised until the court has ruled.

The beneficiary of an exclusive exploitation right (i.e., an exclusive licensee) may, unless otherwise stipulated in the licence agreement, initiate infringement proceedings if, after formal notice, the patent owner does not exercise that right. A non-exclusive licensee is entitled to intervene in the infringement proceedings to obtain compensation for its own prejudice (unfair competition).

Order No. 2018-341 of 9 May 2018 (that will enter into force together with the agreement on the Unified Patent Court) will modify those provisions, so that the exclusive licensee can initiate an infringement action unless otherwise provided for in the licence agreement, and the non-exclusive licensee can initiate an infringement action if expressly allowed in the licence agreement (both subject to prior information to the patent holder).

Standing to initiate a nullity action

In a nullity action, the claimant must demonstrate that the patent is likely to hinder its business activities.

vi Stay of proceedings

A stay of proceedings is automatic when the action is based on a patent application but is optional in other situations. A common example of optional stay is when the validity of a patent is about to be adjudicated upon, for example, by the EPO or in a parallel nullity action.

A party seeking a stay must file a motion at court and attend a hearing, otherwise the application may be ruled as inadmissible. In determining whether to order a stay of proceedings, the focus must be on ensuring a sound administration of justice and must take into account:

  1. the seriousness of the nullity grounds invoked;
  2. the stage of the opposition proceedings; and
  3. the extent of any harmful consequences on the patentee.
vii Statutes of limitationsInfringement actions

Civil actions for infringement are confined in a five-year period. The PACTE law has modified the starting point of this period. Formerly set on the day of the infringement, the new relevant starting point is the day on which the right holder knew or should have known the last fact allowing him or her to initiate the action. Accordingly, it is questionable whether each infringement act would still generate an autonomous time limitation period. It also means that there is a risk of dichotomy between the time for suit and the relevant period for damages.

Depending on the interpretation that will be made by courts, this change could significantly reinforce the rights of the patentees as they could potentially obtain damages for acts committed prior to the five years preceding the launch of the infringement action.

In relation to criminal actions, public prosecution must occur within six years of the day on which the offence was committed.

Nullity actions

In the absence of any specific text for patent nullity action, limitation periods have been ruled by the general provisions of civil law. The limitation period for a patent nullity action was thus five years from the date on which the owner of a right knew or ought to have known the facts that enabled him or her to exercise the action.

The case law pertaining to the starting point of the five-year period has ultimately focused on an in concreto approach to determine, on a case-by-case basis, the date the claimant knew, or ought to have known, the facts that enabled him or her to commence the nullity action.

Statutes of limitation will no longer apply to patent nullity actions, as the PACTE law has modified the IPC to state that 'the patent nullity action shall not be subject to any statutes of limitations'. While legal certainty seems restored, one may nonetheless question how this new rule should be enforced in connection with transitional measures, as it is supposed to apply to 'patents in force' on 24 May 2019, without further indications.

viii Preliminary reliefOverview

Any person with standing to bring an infringement action may request preliminary relief against the alleged infringer or its intermediaries, to stop the infringement or prevent an imminent infringement. In deciding whether to grant preliminary relief, a judge will assess the likelihood of infringement and the seriousness of the invalidity arguments raised by the defendant.

The criteria for assessing the validity of a patent in hearings for preliminary relief are substantially the same as for proceedings on the merits. As such, when validity is raised, it can be difficult for a claimant to obtain preliminary relief. Further, although it is not always clearly stated in the decisions, judges in hearings for preliminary relief tend to adopt an approach that focuses on a balance of convenience and proportionality.

Nevertheless, recent cases show that judges are more inclined to grant preliminary injunctions. For instance, in the healthcare sector, originators obtained significant preliminary injunctions, sometimes even in case of extreme urgency, accompanied by recall measures and significant provisional damages.

If successful, the claimant must initiate an action on the merits within one month of obtaining an order granting preliminary relief.

In theory, such order can be granted ex parte in case of emergency; namely, if any delay would be likely to cause irremediable harm to the claimant. In practice, ex parte preliminary measures are almost never granted in patent matters. The judges consider that such measures should only be available in very extreme cases such as repeated infringement by the same infringer.

Preliminary measures may also be ordered in the course of a proceedings on the merits by the case-management judge. In such case, the defendant can only appeal the measures once a decision on the merits has been reached. This delay can be very damaging for the defendant.


If infringement is found, the judge generally prohibits the continuation of alleged infringing acts. The judge can submit the injunction to securities (to ensure the complainant will be compensated if the injunction is overturned on appeal) although it is rare in practice. The judge can also order the seizure of allegedly infringing products to prevent their introduction or circulation in the commercial channels.

Asset seizures

If the claimant is able to show that there is a risk that recovery of potential damages may be inhibited by the claimant's behaviour, the judge may order the precautionary seizure of the defendant's movable and immovable property. This includes the freezing of the defendant's assets. These measures are rarely applied in practice.

ix Warning letters and risk of unfair competition

Sending a cease-and-desist letter to infringers is not required before initiating an infringement action.

The IPC distinguishes 'direct infringers' (manufacturers and importers) from 'indirect infringers' (distributors). The latter can only be liable for damages if they are aware that their activities may be infringing.

For this reason, patent owners often send warning letters to put indirect infringers on notice. However, great care must be taken while drafting such letters, as it may constitute unfair competition towards the supplier.

Moreover, the question of being on notice regarding potential patent infringement is important in relation to damages because serving a writ of summons has been held to establish awareness for the future: as soon as a distributor receives a writ of summons, it is liable for subsequent acts until the decision on the merits.

Protective letters are not admitted, either to prevent a preliminary injunction or a saisie-contrefaçon. This is compensated by the fact that the seized party can file a motion for withdrawal of the order authorising the saisie-contrefaçon to reintroduce the adversarial principle.