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). Specialization of credit unions to provide financial services to its shareholders requires a particularly strict regulation of membership and acceptable activities. 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. The value of credit unions is not limited to the role of the economic agent - they are an important element of the social structure and a factor of social stability and progress. The right to use the services of the credit union have only its members.