Abstract: In view of carrying out an economic activity, two or more natural persons may set up an association without legal personality. The article has a series of conceptual and practical aspects regarding the declarative and payment obligations that the members of such an entity have. The natural persons achieving incomes within an association without legal personality are obliged to declare them, to pay the income tax and the CAS and CASS to the state budget, under certain conditions. According to the setting up agreement, each associate member has a share within the association, so that it shall owe to the state budget, proportional to its participation, the obtained income tax and social contributions in certain situations. The case studies included describe the way of setting up the declarative and payment obligations corresponding to the activity carried out by the members of a family business, as well as by farmers setting up an association without legal personality, in view of cultivating the lands they possess.