Infringement by equivalence

Infringement by equivalence is the reproduction of a patented invention by a means which differs in form from the one claimed, but which performs the same function with a view to a result of the same nature. It complements literal infringement, in which every feature of the claim is taken identically. Infringement by equivalence prevents a competitor from escaping the patent through a mere variation of form.

The criteria of infringement by equivalence

In French law, the scope of protection is determined by the claims, construed in the light of the description and the drawings, in accordance with Article L. 613-2 of the French Intellectual Property Code and Article 69 of the European Patent Convention. The case law holds that a means is equivalent where it performs the same function as the patented means in order to obtain a result of the same nature. Equivalence is however admitted only if the function itself was new. If the function was already known, the patent protects only the particular form claimed. This functional approach distinguishes French practice from the doctrine of equivalents adopted in other systems.

Infringement by equivalence before the UPC

The Unified Patent Court accepted infringement by equivalence as early as 2024, applying a multi-step test inspired by national approaches. The test verifies that the variant solves the same technical problem, that the extended protection remains proportionate to the contribution of the invention, that the person skilled in the art would have identified the variant as equivalent and that the patent remains valid on that extended reading. The question of equivalence must therefore be anticipated from the drafting of the claims and in any freedom to operate study.

Key points

In practice, infringement by equivalence is a field of technical and legal expertise. The firm argues these questions before the Paris Judicial Court and the UPC, for claimants and defendants alike. See the page bringing a patent infringement action and the entry patent infringement to go further. The text of the Code is available on Légifrance.