Financial institutions in Australia are only permitted to accept deposits from the public if they are authorised deposit-taking institutions (ADIs). The ADI’s authority is granted by the Australian Prudential Regulation Authority (APRA) under the Banking Act 1959 (Cth).

The term was adopted to formalise the right of non-bank financial institutions — such as building societies, credit unions and friendly societies — to accept such deposits. All ADIs are subject to the same prudential standards as banks but for a corporation to use word 'bank', 'building society' and 'credit union' in its name, it must meet certain requirements.

The concept of an ADI replaced that of "bank" following the recommendations of the Wallis Report in March 1997.

The statutory requirements of an ADI are elucidated in case Commissioners of the State Savings Bank of Victoria v Permewan, Wright & Co Ltd (1914). The case was seminal in characterising essential elements of a bank as being the collection of money by receiving deposits upon loan, repayable when and as expressly or impliedly agreed upon, and the utilisation of the money by lending it again in such sums as are required. If this is the institution's real and substantial business, and not merely an ancillary or incidental branch of another business, they are deemed to be a bank.