Like the credit cooperatives, credit unions form associations of a higher level, which are called corporate credit unions. Specialization of credit unions to provide financial services to its shareholders requires a particularly strict regulation of membership and acceptable activities. First central bank of credit unions appeared in 1876. Credit unions began to appear rapidly in many European countries. Credit unions of the open type are still controlled by their members, but at the same time provide services to people who are not its members (external customers). Credit Union - a non-profit financial institution specialized in mutual financial assistance by providing savings and credit services to their members. 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. 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.