School is free until high school in France, and university can be considered as free as well, because it is extremely cheap compared to the USA/Canada/UK for example, and because there is plenty of help to students with low resources.
Friendly fyi: "until" is generally exclusive in English. An similar word that is inclusive is "through". So "I'm on vacation until Monday" implies they will be in the office on Monday, but "I'm on vacation through Monday" implies they will be back Tuesday. I understood what you meant, but for a moment I thought you were saying that you had to pay for highschool in France.
Edit : I was talking about the traffic fines.
Source : I'm French, which may explain my broken English.