Unlike the sales contract, the preliminary contract does not have to be registered with the tax authorities. This lack of fees seems to be an advantage. However, in the event of a dispute relating to the execution of the preconditions, the parties remain bound by the sales contract, except by an amicable agreement or a court decision, in the case of a unilateral sales contract, the parties regain their freedom. If the option is not enforced by the contract of sale (also known as a “unilateral preliminary contract”), the owner has agreed with the potential buyer (known as the beneficiary) to sell his property to him at a set price. This results in an exclusive “option” for a limited time (usually two to three months). The buyer is entitled to a reflection period of ten days after the signing of the sales contract. . . .