The Association of Southern Credit Unions (ASCU) was formed at a meeting held at the Illawarra Master Builders Club on 27 August 1965. It was formally registered several months later. The ASCU was the first association of NSW credit unions formed due to dissatisfaction with the administration of the NSW Credit Union League (later the Association of NSW Credit Unions).

Initially established to encourage and promote credit unions on the South Coast of NSW, as early as March 1966 membership was opened to credit unions in the Sutherland and Nowra areas. By 1969 there were 16 member credit unions from the Illawarra, Newcastle and Sydney.

A forum on 8 February 1982 considered proposals to form a single association for credit unions in NSW. The Association of Southern Credit Unions joined the newly named Association of New South Wales Credit Unions on 1 November 1982.

The Australian Mutuals Archives’ collection of ASCU material includes annual reports, meeting minutes, a members register, governance documents, seminar papers and newsletters.