Given the renewed and growing importance of the initiative of the private sector in developing public infrastructure and public utilities, especially as a consequence of the incentives created by the law, this study intends to address the various aspects of the new legal framework for the formation of concession contracts as a result of a particular initiative or idea and not as a product of the needs defined by the Administration, with a particular emphasis on the requirements for the formation of public works concessions, but without forgetting how the mechanism of private initiative applies to public utilities when they require a concession contract to be provided.