Membership in the credit union is voluntary and is open to all citizens bound by with joint work or residence, who wished to create a credit union to use its services and are willing to take on relevant commitments and responsibilities. Among the U.S. credit unions, there are three groups that differ in terms of assets, shareholders, and business services. 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. Credit cooperatives and credit unions exist in many different forms. The main differences relate to the nature of the membership and the opening of a credit institution.