The rules of preferential origin allow a good to benefit from a reduction or exemption from customs duties, as part of a preferential relationship concluded with the European Union (EU).
The preferential origin of a good can only be determined within the framework of a preferential relationship concluded with the EU. In this case, the framework is the Trade and Cooperation Agreement with the United Kingdom
For more details on determining the preferential origin on a general level, you can consult the guide published by the DGDDI (French General Directorate for Customs):
You can also contact the Economic Action Unit (Pôle d'action économique) of the Regional Customs Directorate in your area.
https://www.douane.gouv.fr/les-cellules-conseil-aux-entreprises
