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.). 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. Specialization of credit unions to provide financial services to its shareholders requires a particularly strict regulation of membership and acceptable activities. Income derived from the provision of services to its members, does not become the profit of credit union and is distributed among its members in proportion to their savings. 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 unions are competitors of savings institutions, adding interest on deposits of members. This applies to the shares, as well as to additional funds transferred to the account in the credit union. Shareholders in corporate organizations are basic credit unions, besides the same union can be a shareholder of several corporate organizations. The supreme body of the World Council of Credit Unions is the Assembly, which elects the president and the board of directors of WOCCU.