Fund of Mutual Financial Aid of the credit union can be extended by sponsorship contributions from businesses, organizations, including on a returnable basis. Corporate credit unions are united on a cooperative basis in the Central Credit Union (US Central Credit Union). 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. As of the January 1, 2012 the national associations and confederations unite more than 196 million members participating in the 51,013 credit unions in 100 countries. 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. Contributions from of shareholders in credit unions in no way can be considered as borrowed funds, they come from the shareholders and for the shareholders and can not be used to provide services to third parties. Taking a decision to join a credit union, citizens create an organization through which they participate in the shared savings by mutual crediting and joint (collective) use of personal savings.