Corporate credit unions are united on a cooperative basis in the Central Credit Union (US Central Credit Union). National Credit Union Administration (NCUA) - an independent federal agency, based in Washington (State of Columbia), established by the U.S. Congress to oversee the federal credit union system. National Credit Union Insurance Fund was created by Congress in 1970 to insure deposits of credit union members in the amount of 100 thousand dollars. 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.