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. 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. Income received by the credit union shall be distributed among the shareholders or spent for the depreciation of services, that is, are the most effective means of meeting the needs of shareholders. First central bank of credit unions appeared in 1876. Credit unions began to appear rapidly in many European countries. 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. International cooperation has been particularly felt since the days when Alphonse Desjardins began the activity on development of credit union movement in North America. 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.