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. Like the credit cooperatives, credit unions form associations of a higher level, which are called corporate credit unions. The number of shareholders of a credit union is limited and formalized by a list. Limit of the number is defined by the assembly and such assembly establishes the charter. Credit union is created by a group of members who pursue a common interest. Agreeing to make regular contributions, they create a fund from which can borrow money for investments and replenishment of working capital at favorable interest rates. Specialization of credit unions to provide financial services to its shareholders requires a particularly strict regulation of membership and acceptable activities. To reduce the risk of default on loans members of the credit union shall the joint guarantee. 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.