Can unwed partner stay in French home?

These are the same thing and yes, it is true, says honorary avocat Gerard Barron.

It needs no confirmation in a will, although if the owner dies leaving children as claimants to their estate, it would be best for the will to say "subject to the commodat in favour of X, I leave my estate to Y". This would give rise to death duties on the continuing right of occupation, which would be valued on the same basis as a life interest (usufruit). As the beneficiary is unrelated to the owner, the rate of tax would be 60%.

A commodat needs careful drafting in relation to matters such as responsibility for upkeep, local tax and insurance, and there should be provisions relating to the beneficiary's rights ending in the even of the couple separating before the owner dies.