Actually, CB (for "Carte Bleue") looks so close to the generic "carte bancaire" word for "bank card", that few people even know that it's just a national card thing.

I don't know if stores are allowed to charge customers differently for different payment means, but I guess not since I have never seen it. However some stores only take cards for a minimum amount. The largest chains though don't have any limit, and I've actually already paid amounts less than 1€ with my card.

But people actually still often say "carte bleue" to refer to any kind of payment card (even a Mastercard one). Apparently just because it was the name of the first payment card in France.

So yeah, you have to swap carte bleue and carte bancaire in my previous post, I guess.

Need to implement? There still is such a thing - albeit not much of it - as independent national legislation, even in these nightmarish sunsetting years of the EU.