The South Australian Public Service Savings and Loans Society was formed when a general meeting of members of the Public Service Association on 28 April 1949 voted for its establishment.  The first Board was elected on 17 May 1949.  The original office in Adelaide was in the Rechabite Chambers, Victoria Square and by June 1950 there were 131 members.

In 1979 the Savings and Loans Society moved to new premises in Wakefield Street.  Various modernisations followed – including a New Wang computer system acquired in 1980 and the introduction of on-line automatic updating of accounts.  The following year a regular bill-paying service, children's accounts, cheque-a-month investment accounts, automatic teller machines and fixed deposit accounts were introduced.

By the early 1980s there was a head office and 17 service centres. The Savings and Loans Society continued to flourish and it accepted the engagements of SAGASCO Employees' Credit Union Ltd (August 1988), Warwick Co-Operative Credit Union Ltd (June 1990) and the SATAB Credit Union Ltd (November 1991).

In 1992 regulations under the Credit Union Act required every credit union to have the words ‘credit union’ in its official title.  Discussions ensued and the names ‘Capital’, ‘Premier’ and ‘Horizon’ were all considered.  However a Special General Meeting in 1994 approved the name change to Savings and Loans Credit Union (SA) Ltd.

The credit union was very successful and by 1995/96 it had approximately 70,000 members and $450 million in assets. By 1997 there were 15 branches and 36 automatic teller machines.  In March 2000 the first Northern Territory Branch was opened at Palmerston.   This was followed by a branch at Darwin in 2004. The first Victorian branch was opened at Warrnambool in 2003.

In 1999 the credit union celebrated its 50th anniversary and at that time it had 125,000 members and nearly 800 million dollars in assets.

The credit union continued to expand and it accepted the engagements of the NRMA Employees’ Credit Union Ltd, a small New South Wales based credit union, on 25 May 2005. On 1 November 2008, the Austral Credit Union merged with Savings and Loans (SA) Ltd.

The Savings and Loans Credit Union (SA) Ltd merged with Australian Central Credit Union on 1 December 2009. At the time of the merger news items noted that the merged entity would have around 350,000 members and more than $7 billion in assets, making it the second-largest credit union in Australia.