Article L145-55 of the French Commercial code
At any time and until the expiry of a period of fifteen days from the date on which the decision has become res judicata, the tenant who has made a request in accordance with articles L. 145-47, L. 145-48 or L. 145-49 may waive it by notifying the lessor by extrajudicial act or by registered letter with acknowledgement of receipt, in which case the lessor shall bear all the costs…