Can a decision to grant a patent be contested ?

The grant of a patent gives its holder strong protection, but it does not place that protection beyond dispute. A competitor, a licensee or a defendant in infringement proceedings may challenge a patent after grant, before the office that granted it or before the courts. The available routes, time limits and grounds vary according to the title concerned and the forum seised.

The grant of the patent

A patent is an industrial property right that gives its holder exclusive rights to exploit an invention for a maximum of twenty years from the filing date of the application, provided the renewal fees are paid. The invention must be new, involve an inventive step and be susceptible of industrial application.

In France, the National Institute of Industrial Property (INPI) grants national patents. The European patent is granted by the European Patent Office (EPO) following a centralised procedure. Since 1 June 2023, the proprietor of a European patent may also request unitary effect, which provides uniform protection in the participating Member States of the European Union, eighteen since Romania joined in September 2024.

Challenging a patent before the office

Opposition before the EPO

Any third party may file an opposition against a European patent within nine months of the publication of the mention of its grant. Opposition seeks the revocation of the patent in whole or in part. It rests on limited grounds: lack of patentability, in particular for want of novelty or inventive step, insufficiency of disclosure, and extension of the subject matter of the patent beyond the application as filed. The procedure is adversarial and the opponent must properly substantiate its case.

The effect of the decision depends on its outcome. Revocation by the EPO applies in all designated States, and the patent is deemed never to have had any effect. A decision maintaining the patent, by contrast, binds neither the national courts nor the UPC, which may take a different view of its validity.

Opposition before the INPI

Since 1 April 2020, French patents have been subject to a comparable opposition procedure. It is filed with the INPI within nine months of the publication of the grant in the Bulletin officiel de la propriété industrielle. Its decision may be appealed before the Paris Court of Appeal.

Invalidity before the courts

Invalidity may be sought at any time, without waiting for the opposition period to expire. It is very often raised in defence, by way of counterclaim, in infringement proceedings.

In France, the Paris Judicial Court

For French patents and European patents in force in France, litigation falls within the exclusive jurisdiction of the Paris Judicial Court, with appeals to the Paris Court of Appeal.

Before the Unified Patent Court

Since 1 June 2023, the Unified Patent Court (UPC) has heard disputes concerning European patents with unitary effect and classic European patents. During a transitional period of seven years, which may be extended, the proprietor of a classic European patent may remove it from the Court’s jurisdiction by an opt-out, which takes effect for the whole life of the patent unless withdrawn. During that same period, actions concerning European patents that have not been opted out may still be brought before national courts.

The UPC hears invalidity actions, actions for a declaration of non-infringement and infringement actions, to which defendants frequently respond with a counterclaim for invalidity.

Grounds of invalidity

A patent is liable to be declared invalid where it does not satisfy the conditions of patentability. The invention may lack novelty, because it was already available to the public before the filing date. It may lack inventive step, where it follows obviously from the state of the art for the person skilled in the art. It may also not be susceptible of industrial application, because it cannot be made or used in any kind of industry. Invalidity is also incurred where the description does not disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art, or where the subject matter of the patent extends beyond the content of the application as filed.

Certain subject matter is, moreover, excluded from patentability. Discoveries, mathematical methods and computer programs are not inventions when claimed as such. Also excluded are methods of surgical or therapeutic treatment and diagnostic methods practised on the human or animal body, plant varieties and animal breeds, and inventions whose commercial exploitation would be contrary to ordre public or morality, which covers in particular certain uses of human embryos.

The purpose of a challenge

A challenge is often defensive. Sued for infringement, the defendant seeks to bring down the patent in order to escape liability. It may also be offensive, where a market player considers that a patent hinders the legitimate exploitation of a technology or the working of competition.

Related routes

Declaration of non-infringement

A company preparing to launch a product may, without waiting to be sued, ask the court to declare that its exploitation does not infringe the patent. This declaratory action secures the project in advance. Under French law, it requires evidence of exploitation or of serious preparations, and the patent holder must first have been invited to take a position.

Competition law

Holding or exploiting a patent may also be examined under competition law, in particular where the patent is essential to a technical standard or where the holder uses it abusively to shut a competitor out of the market. Actions for abuse of a dominant position or for anticompetitive practices may then be brought. They leave the validity of the title untouched and concern the conditions under which it is exercised.

A title that remains exposed

Grant does not settle the validity of a patent once and for all. The title remains exposed to opposition before the office and to invalidity actions before the courts, and its reach may be circumscribed by an action for a declaration of non-infringement. For the holder, the strength of the patent is built at the drafting stage, through claims that meet the substantive conditions. For competitors, these remedies regulate the system and preserve the balance between the protection of innovation and freedom of competition.