Complex contract negotiations usually, after an initial stage of estimation of the project’s feasibility followed by preliminary negotiations, lead to a request for offers within a time limit. This preliminary stage is at the core of the pre-contractual negotiation and can lead to a cooperation between the future partners.

Some contracts seem likely to be concluded instantaneously by the meeting of the offer and acceptance. This seems to be the case for a sales contract in French law and in some continental laws, when the fundamental elements of the transactions are defined. The offer and acceptance put on a determining nature and constitute, depending on the parties’ attitude, factors of success or hazards. However, contracts for services only seem to be formed once some details have been finalized and after a subsequent elaboration of a contract.

Nevertheless practice often reveals, in the offer as well as in the acceptance, the frequent presence of the formula “subject to contract”- a superfluous indication or constitutive of a false meaning, if the offer and acceptance are followed in most cases by the signature of a formal contract. Except for considering that this formula enables to clarify the parties’ intent by illustrating their intent of not immediately and completely concluding, at the risk of blurring their common intent, if this formula is assimilated to a kind of condition to the conclusion of the definite contract.