Like any financial institution, credit unions have the financial resources. The difference between credit unions and banks is clearly is apparent when comparing the structure of assets and liabilities of credit unions and banks. Is necessary that all shareholders of the credit union were members of a single community, would know each other well enough to enjoy mutual trust. 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. 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. 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). As of the January 1, 2012 the national associations and confederations unite more than 196 million members participating in the 51,013 credit unions in 100 countries. Unlike banks, in order to use the services of a credit union, you have to become its member, having written an application and having paid thus shares and membership fee.