An EAN-13 code starting with 300–379 was issued to a company registered with the GS1 organisation of France and Monaco. It is a clue about the company, not the factory.
GS1 allocates prefixes by country. Companies registered with GS1 France and Monaco receive codes starting with 300–379. They keep that prefix even when they manufacture elsewhere or sell worldwide.
So a product with prefix 30–37 may be made outside France and Monaco, and a product made in France and Monaco may carry another country’s prefix if the brand is registered there.
Look for “Made in”, “Produced in”, “Country of origin” or “Origin” on the label. In the EU, fresh meat, fresh fruit and vegetables, unprocessed fish, eggs, honey and virgin and extra virgin olive oil must state their origin.
If you do not have the label at hand, scan the barcode with Origen: it shows the manufacturing country stated in Open Food Facts and related databases, or tells you when it is missing.
It means the company registered the code with the GS1 organisation of France and Monaco. The product may have been made in another country: check the label or scan it with Origen.
The label wins. The country of origin or “Made in” shows where it was made; the prefix only shows where the company is registered.
Open Origen, scan the barcode and you will see the manufacturing country and ingredient origins when the public product record states them.