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. Credit union promotes the effective conservation of personal funds of its members, giving them the loans from the funds of the credit union, as well as the sharing of savings in education, housing, health care and other programs of social support and social development of its members. Until the 70's there was a proliferation of the U.S. credit unions due to the increase of their number and the number of shareholders, although it must be acknowledged that there was also and a qualitative growth. Income derived from the provision of services to its members, does not become the profit of credit union and is distributed among its members in proportion to their savings. 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 case of default the shareholder - individual will respond with its property and, in addition, is jointly and severally liable with the credit union's commitments. 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.