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. 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. Since the early 80's started the process of consolidation of credit unions, leading to a decrease in their number with a simultaneous increase in the total number of members. Taking a decision to join a credit union, citizens create an organization through which they participate in the shared savings by mutual crediting and joint (collective) use of personal savings. Credit unions encourage the proper use of shareholders savings, developing social programs (education, health, recreation, housing, etc.).