Australia’s Big Four Banks: Everything You Need to Know

 

 

Understanding the Big Four Banks in Australia

The Top Four banks play a key role in shaping Australia’s banking landscape. These major institutions include:

• -Commonwealth Bank of Australia (CBA)

• -Westpac Banking Corporation

• -National Australia Bank (NAB)

• -ANZ Banking Group

They work closely with the government and the Reserve Bank of Australia to support economic stability and maintain credit flow. While the COVID-19 pandemic affected profits, these banks have since focused on digital innovation and productivity to drive growth.

Who Are the Big Four Banks?

The term “Big Four” refers to the four largest banks in Australia by market share and customer base. Their size, influence, and long history have made them trusted financial institutions for millions of Australians.

What Do They Offer?

These 4 major banks provide a wide range of products:

• -Transaction and savings accounts

• -Term deposits

• -Home and personal loans

• -Credit cards

• -Business banking services

They hold a dominant share of the lending market, with 75.2% of residential home lending value across Australian banks — around $1.6 trillion.

Each bank also offers online and mobile banking. However, the user experience can differ. If digital banking is important to you, consider testing their apps before deciding.

Are the Big Four Banks Safe?

Yes, but so are other Australian banks. While their size and brand recognition give the Big Four a reputation for safety, all Australian banks are protected under the Government Guarantee. This covers up to $250,000 per person, per institution, in the event of a financial crisis.

[🔗 Australian Government Guarantee information 
[🔗 Compare bank accounts in Australia 

Market Position: Big Four Bank Rankings (2026)

Market capitalisation, or market cap is calculated by multiplying the price of a stock by the total number of outstanding shares. Based on data from the Australian Prudential Regulation Authority (APRA):

1. 1-Commonwealth Bank of Australia (CBA) – $1.215 trillion

2. 2-Westpac Banking Corporation – $1.144 trillion

3. 3-National Australia Bank (NAB) – $979 billion

4. 4-ANZ Banking Group – $751.056 billion

CBA has led the market for decades, partly due to its early role as a government-owned bank and as Australia’s central bank before 1960. Westpac consistently ranks second in assets, although its market capitalisation sometimes fluctuates. NAB and ANZ have traditionally competed for the third spot, with NAB currently ahead.

Key Differences and Considerations

While the Top Four banks share many similarities, there are also differences in:

• -Digital experience

• -Customer service

• -Interest rates and fees

• -App performance

• -Product bundles and rewards

If you’re deciding between them, think about what matters most: Do you value a strong digital platform? Lower fees? Convenient branch access?

 

 

Which of the Top four banks is largest for home loans?

Monthly ADI figures from April 2025 show the total value of mortgage owner occupier lending for the big four banks at:

 

• -CommBank: $386.997 billion.

• -Westpac: $321.141 billion.

• -NAB: $219.562 billion.

• -ANZ: $209.891billion.

CommBank is also the largest in-home loans to investors, followed by Westpac, NAB and then ANZ. The April 2025 monthly ADI figures show the value of investment home loan lending for the top four Australian banks at:

 

• -Comm Bank: $198.960 billion

• -Westpac: $162.976 billion

• -NAB: $110.905 billion

• -ANZ: $104.421 billion.

 

Which Other Banks or Financial Institutions Are Owned by the Big Four?

In addition to their main brands, the top Four banks each own or hold stakes in a range of other banks and financial companies. This network of ownership means that many well-known names you encounter are actually backed by one of these major players. Here’s a snapshot of some notable subsidiaries and associated entities:

 

• a-Commonwealth Bank of Australia (CBA): Owns Bankwest and digital home loan provider Unloan. CBA also retains significant stakes in Colonial First State and the Lendi Group (following the merger of Lendi and Aussie).
• b-Westpac: Oversees St.George, Bank of Melbourne, BankSA, and the home loan specialist RAMS. Their financial services group also includes the wealth management brand BT.
• c-National Australia Bank (NAB): Owns the digital bank ubank. NAB also acquired 86 400, a neobank which has now merged with ubank.
• d-ANZ: Recently expanded its presence by acquiring Suncorp Bank.

Because these banks have such a large footprint, it’s common for Australians to use products from these subsidiaries without realizing they’re part of a bigger group. If you value banking with a smaller or more niche institution, it’s worth checking their ownership structure before making your decision.

 

Cons of Banking with the Big Four

While Australia’s big four banks offer scale and familiarity, there are some drawbacks worth considering.

 

Rates may not always be the most competitive
Because of their size, extensive branch networks, and higher operating costs, the big four don’t always lead on pricing. This can mean lower interest rates on savings accounts and, in some cases, less competitive home loan rates compared to smaller lenders, mutual banks, or digital providers.

 

Fees can add up
Some everyday transaction accounts come with monthly fees unless specific conditions are met, such as minimum deposits or spending thresholds. Additional charges may also apply for services like international transfers, foreign currency transactions, or replacing lost cards. By comparison, many smaller or digital lenders offer low-fee or fee-free accounts with fewer requirements.

 

Less personalised service
With millions of customers, service at the big four can feel more standardised and process-driven. In contrast, customer-owned and smaller banks often place greater emphasis on personalised support, community engagement, and building long-term relationships with their members.

 

Top 10 Australian Banks – Market Capitalisation 2026

Rank	Bank & ASX Sign	Market Cap – April 2026 ($AUD billion)
1	Commonwealth Bank – CBA	$293.56
2	Westpac Banking Corporation – WBC	$138.52
3	National Australia Bank – NAB	$130.28
4	Australia & New Zealand Banking Corp – ANZ	$111.87
5	Macquarie Group – MQG	$80.45
6	Bendigo & Adelaide Bank – BEN	$5.96
7	Bank of Queensland – BOQ	$4.75
8	Judo Bank – JDO	$1.51
9	Heartland Group – HGH	$0.92
10	MyState – MYS	$0.76

 

Summary

The Big Four banks continue to hold a dominant place in Australia’s financial sector. Their size, product range, and integration with national economic policy make them reliable choices. Still, with all Australian banks offering the same deposit protection, it’s wise to compare your options based on your individual needs.

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[🔗 APRA data on bank assets