Total assets of Australian banks are estimated to be approximately A$4.0 trillion. ANZ, Commonwealth, Westpac and National Australia Bank are the four largest domestic banks providing a complete range of retail and corporate banking services. Each has an AA rating. Only nine of the top 100 banks globally enjoy a rating of AA or higher. The Australian government has a "four pillars" policy that prevents mergers between four major banks. The banking regulation in the country is extensive and detailed. It is split between APRA (Australian Prudential Regulation Authority) and ASIC (Australian Securities and Investment Commission). APRA, established in 1998, controls the credit unions, banks, building and friendly societies, insurance companies as well as members of the superannuation sector. The superannuation industry is a significant part of financial system. Total assets in the sector amount to approximately $2 trillion or 50% the Australian banking system. Foreign banks are also well represented in the Australian market. The majority of them are focused on commercial banking and capital market activities.
Five Largest Banks
| Rank | Bank | Total assets, A$b | Loans, A$b | Deposits, A$b | Balance Sheet |
| 1 | Commonwealth Bank of Australia | 978.046 | 749.858 | 610.385 | 30.06.2017 |
| 2 | ANZ Banking Group | 896.511 | 564.035 | 581.407 | 31.03.2017 |
| 3 | Westpac | 839.993 | 667.000 | 522.513 | 31.03.2017 |
| 4 | National Australia Bank | 790.227 | 520.954 | 487.252 | 31.03.2017 |
| 5 | Macquarie Group | 182.877 | 76.663 | 57.708 | 31.03.2017 |
Customer Satisfaction Rating:
Credit Unions: 88.1%
Building Societies: 90.6%
Banks: 74.3%
Major Banks: 78.9%
(Source: Roy Morgan Research)
Five Largest Credit Unions
| Rank | Name | State | Assets (A$m, 2015 FY) | Deposits (A$m, 2015 FY) |
| 1 | Credit Union Australia | QLD | 11,990 | 7,780 |
| 2 | People's Choice Credit Union | SA | 6,895 | 4,986 |
| 3 | Qantas Credit Union | NSW | 3,127 | 2,820 |
| 4 | Bananacoast Community Credit Union | NSW | 1,463 | 1,304 |
| 5 | Queensland Country Credit Union | QLD | 1,205 | 1,075 |