Membership in the credit union is voluntary and is open to all citizens bound by with joint work or residence, who wished to create a credit union to use its services and are willing to take on relevant commitments and responsibilities. In the U.S., credit unions have a clear organizational structure. All credit unions belong to one or the other parent credit union (there are 35 of them in the U.S.). 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. The main advantage of credit unions consists in transparency, controllability, governance for shareholders. Until the mid-XX century, credit unions in the United States had little assets that did not exceed, as a rule, 100 thousand dollars Historically, credit unions have grown from the experience of credit cooperatives, but they took the experience of organizations of mutual aid of citizens by moving methods of social self-protection from labor and toward consumption. Credit unions, like today's credit unions, emerged in the 19th century in Germany as a result of crop failure and famine. Credit union as a consumer cooperative operates on the principles of equality of all its members.