Article L2192-10 of the French Public procurement code
The contracting authorities, including those acting as contracting entities, shall pay the sums due in principal under a contract within the time-limit laid down in the contract or, failing that, within the time-limit laid down by regulation, which may differ according to the category of contracting authority.Where a time-limit for payment is laid down in the contract, it may not exceed the time-limit laid down by regulation.