For the evolution of social reality, the contracts characterized by the immediacy between the declarations of will coexist with other contracts
realized with no simultaneous declarations of will and reach a great practical importance. The main problem of these contracts is the need of a legal framework that introduces sufficient elements to provide security, integrity and the protection of the interests of the parties when they are not present. In this regard, this article describes how this type of contract between absents become perfect, focusing into into Spanish legal regulation, exposing the solutions that comparative law presents and finally concluding with the proposal of Modernization of the European contractual Law that is expected in the future.