In the U.S., credit unions have a clear organizational structure. All credit unions belong to one or the other parent credit union (there are 35 of them in the U.S.). Like any financial institution, credit unions have the financial resources. Income received by the credit union shall be distributed among the shareholders or spent for the depreciation of services, that is, are the most effective means of meeting the needs of shareholders. 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. Members of credit unions place in credit unions usually free fund balances, ie those that remain after expenses devoted to education of children, the acquisition of new properties, additional pension benefits, etc. 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.