Fund of Mutual Financial Aid of the credit union can be extended by sponsorship contributions from businesses, organizations, including on a returnable basis. Some credit unions are closed, serving only their members. However, the more and more popularitywin cooperatives of open type. 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. In the U.S. credit unions timely and full repayment of loans is a common phenomenon. Unpaid and delinquent loans are not more than 3% of their amount. To reduce the risk of default on loans members of the credit union shall the joint guarantee.