What is the role of the Legal Expert in Intellectual Property?

The Legal Expert’s role is to give an opinion on precise technical points. He or she can be designated by the Judge or by parties to the proceeding.  Legal experts are present in all fields where a technical opinion may be required, for example for medicine, architecture, law, which of course includes Intellectual Property law.


What is the “specific” role of the Legal Expert in Intellectual Property?


Technicality and technicity are at the heart of intellectual property.  Innovation and creation are the essence of this subject. Therefore, resorting to Experts is often mandatory to analyze, explain or interpret an Inventor’s invention or a Creative’s creation from a technical point of view.


For example, the Legal Expert in Intellectual Property may be called upon to evaluate the prejudices caused by an infringement of an Intellectual Property Right, which are often difficult to estimate, particularly in the case of Trademarks. More generally, the expert may examine the technical evidence or question  parties in order to provide an impartial opinion.


It is important to note, that the judge is not required to follow the Expert’s recommendations, however they may rely on the Expert’s report or testimony at the hearing as a basis for their decision.


How are Legal Experts in Intellectual Property appointed?


There are two distinct ways to designate a Legal Expert during a legal proceeding.

Firstly, a  Judge will call upon the experts registered on the National lists. The Experts are specialized and there are several lists available that classify Experts by specialty and subspecialties. . One list is made by the French Cour de cassation (Supreme Court) and there is also one list via the Appeal Courts. Secondly, the parties to the proceeding may  also directly contact a Legal Expert of their choice.  This Expert may not be on the lists of the Cour de cassation or the Appeal Courts. In this case, the Expert will have to take an oath before a  Judge at the time of the hearing.


What is the role of Dreyfus & associés ?


Dreyfus is an Industrial Property law firm based in Paris.

Nathalie Dreyfus, founder of Dreyfus & associés, is a registered Legal Expert before the Paris Court of Appeal for specialty E.09.02 Industrial Property – Trademarks. In December, 2022, she was named as a Legal Expert before the French Cour de cassation (Supreme Court) for the same specialty.

The Legal Expert in Intellectual Property is above all  a technical and Legal Expert in one or more Intellectual Property specialties, having several years of experience practicing Intellectual Property Law.

The process involves the Legal Expert intervening  in a legal proceeding to provide their  expertise on a Trademark, a Patent or a design’s technical aspects and in so doing,  they help the Judge to motivate towards a decision.



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We offer our clients a dedicated and unique experience of expertise that is necessary for the exploitation of intangible assets.  We will also endeavor to keep you informed and up-to-date about intellectual property and digital economic issues through our articles and newsletters written by the Dreyfus Legal Team.