Fund of Mutual Financial Aid of the credit union can be extended by sponsorship contributions from businesses, organizations, including on a returnable basis. The number of shareholders of a credit union is limited and formalized by a list. Limit of the number is defined by the assembly and such assembly establishes the charter. Specialization of credit unions to provide financial services to its shareholders requires a particularly strict regulation of membership and acceptable activities. Credit unions are competitors of savings institutions, adding interest on deposits of members. This applies to the shares, as well as to additional funds transferred to the account in the credit union. The right to use the services of the credit union have only its members. Credit cooperatives and credit unions exist in many different forms. The main differences relate to the nature of the membership and the opening of a credit institution.