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 uniqueness of credit unions is that they put together the principles and benefits of financial cooperatives, consumer cooperatives and mutual aid funds, born once by trade unions. To reduce the risk of default on loans members of the credit union shall the joint guarantee. 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. Credit unions base their activities on savings of shareholders, their shares and savings contributions, which make up the fund of mutual financial assistance - a source of cash loans to shareholders. A credit union on its own initiative order is created by citizens (individuals) to solve their financial problems that they could not solve in other financial institutions. 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.