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. Corporate credit unions are united on a cooperative basis in the Central Credit Union (US Central Credit Union). Typically, donor contributions to the credit unions are targeted and used in the same statutory requirements and restrictions as the Mutual Financial Aid fund as a whole. Principles of cooperative democracy and interaction were adequate to the purposes for which people joined credit unions. The main activities of credit unions, aimed at the organization of mutual aid and social support of citizens is not intended to profit. In the UK, credit unions are a source of financing of people groups. This tool is not widely used. 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. Credit unions historically formed as a special form of social support, initially taken upon themselves the social mission of protecting the interests of citizens in the field of financial services. On the consumer credit market in the U.S. credit unions are on the third place after the commercial banks and finance companies and are ahead of savings institutions, not taking into account the loans on real estate.