Abstract: The aim of this article is to understand the two ways of setting up share companies (SAs) and partnerships limited by shares (SCAs) – through full and simultaneous subscription and through public subscription –, the analysis of the SAs and SCAs set up through public subscription, knowing the role of the constituent assembly and the role of the founders in the set up phase of SAs and SCAs, as well as the conditions for the set up of branches and subsidiaries.