Some credit unions are closed, serving only their members. However, the more and more popularitywin cooperatives of open type. Credit unions also differ from the traditional consumer cooperatives. 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. At the organization of the credit union it is important that people know each other and know the extent to which each of them is trustworthy. Cooperation between credit unions, how they would not have been named, took place always, from the moment when the movement moved outside one credit union. To reduce the risk of default on loans members of the credit union shall the joint guarantee. 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). Credit unions encourage the proper use of shareholders savings, developing social programs (education, health, recreation, housing, etc.). Today, the World Council of Credit Unions is represented as members four regional confederations and twelve national associations. 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.