Since electronic contracts are currently taken as seriously as offline contracts, the same principles apply to a valid contract. The law already recognizes contracts with fax, telex and other similar technologies. An agreement between the parties is valid if it meets the legal requirements of its conclusion, i.e. the parties wanted above all to establish a contract. This intention is demonstrated by the respect of 3 classic cornerstones, that is to say the offer, the acceptance and the balancing. A difficult task in concluding an electronic contract is to know when an agreement has been reached. As soon as an offer is accepted, a contract is concluded, the postal acceptance rule does not apply. The postal acceptance rule is an exception to the general rule that the acceptance of a contract must be notified to the supplier before a contract is concluded. The rule provides for the acceptance of a contract at the time of signing the acceptance.