Activity of the credit union consists of organizing mutual financial assistance by meeting the needs of its members in the services of saving and obtaining loans. 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. Cooperation between credit unions, how they would not have been named, took place always, from the moment when the movement moved outside one credit union. The relationship between credit unions and shareholders arise from the membership and are not customer relationship. In the UK, credit unions are a source of financing of people groups. This tool is not widely used. 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. Credit unions historically formed as a special form of social support, initially taken upon themselves the social mission of protecting the interests of citizens in the field of financial services.