Principles of cooperative democracy and interaction were adequate to the purposes for which people joined credit unions. 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. Among the U.S. credit unions, there are three groups that differ in terms of assets, shareholders, and business services. National Credit Union Insurance Fund was created by Congress in 1970 to insure deposits of credit union members in the amount of 100 thousand dollars. Credit unions encourage the proper use of shareholders savings, developing social programs (education, health, recreation, housing, etc.). 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. On the consumer credit market in the U.S. credit unions are on the third place after the commercial banks and finance companies and are ahead of savings institutions, not taking into account the loans on real estate. Worldwide credit union movement is represented by regional confederations and national organizations within the World Council of Credit Unions. A potential new member of a credit union must submit a recommendation of shareholders in which the referee becomes a warrant of a future member of the credit union.