A potential new member of a credit union must submit a recommendation of shareholders in which the referee becomes a warrant of a future member of the credit union. Credit unions of the open type are still controlled by their members, but at the same time provide services to people who are not its members (external customers). In the credit union compensation for use of the loan (interest) is a source of compensation for savings. The relationship between credit unions and shareholders arise from the membership and are not customer relationship. 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. The right to use the services of the credit union have only its members. Corporate alliances are intermediaries between credit unions and financial markets.