Which of the Big Four Australian Banks Should I Bank With?

Australia’s banking sector is dominated by four major banks collectively known as the ‘Big Four’ – Commonwealth Bank of Australia (CBA), Westpac, National Australia Bank (NAB), and Australia and New Zealand Banking Group (ANZ). 

The Big Four commands more than 70% of the total market share in the country’s financial sector, possessing combined assets exceeding $3.77 trillion as of early 2024. Australia’s entire banking sector is valued at over $5.31 trillion.

These figures comprise residents’ assets such as loans, deposits, and other financial holdings. 

Source: APRA, February 2024

By comparison, the top 5-10 banks’ aggregate assets are worth $743.70 million – only a little over the total assets of the smallest of the Big Four.

What sets the big four banks apart from their peers, apart from sheer scale, is that they must abide by the Four Pillars Policy. This law essentially bans these four banks from ever merging. Other banks are ripe for the picking, however – subject to regulatory approval – as you’ll see below. The majors have been prolific over the past 20 or so years in expanding their footprints via the acquisition of smaller players.

Despite the undeniable preference for the country’s four majors, they, along with other banks and financial institutions, are all regulated by the Australian Prudential Regulation Authority (APRA), the Australian Securities and Investment Commission (ASIC), the Reserve Bank of Australia (RBA), and the Department of Treasury. 

Ranking the Big Four Banks

Source: ASX, March 2024

1. Commonwealth Bank - CBA

While CBA is the youngest of the four following its establishment in 1911, and privatisation in 1996, it holds the title of Australia’s largest bank. It leads not only in terms of total assets but also by market capitalisation. Until the 1990s CBA enjoyed decades of being a government-owned institution, and served as the central bank until the RBA took over this function in 1960. 

2. National Australia Bank - NAB

NAB was formed through the merger of century-old banks Commercial Banking Company of Sydney (1834) and National Bank of Australasia (1858), and settles in the second spot - at least in terms of market cap. Its total assets include those held by its subsidiaries UBank and Bank of New Zealand. In the past few years, it also acquired neobank :86 400 (which was absorbed into UBank), and Citi’s retail banking portfolio.

3. Westpac - WBC

Westpac has cemented its place in the third spot in terms of market capitalisation. However, it actually ranks second by many other metrics as you’ll see below.

This was made possible following its merger with St George Bank in 2008, which was the fifth largest bank in Australia at the time. It also acquired BankSA and RAMS in the same year and Bank of Melbourne years earlier.

4. Australia & New Zealand Banking Group - ANZ

ANZ is currently the smallest of the Big Four, but it is set to get bigger depending on the Treasury’s final decision on its $5-billion takeover of Suncorp Bank. If the proposal is greenlit, it will propel the ANZ’s assets to over $800 billion. Suncorp’s banking arm is among the 10 largest in Australia.

Which of the Big Four is the best bank for saving?

Based on the volume of deposits they hold, many Australians obviously trust the Big Four much more than others with their money. The combined household deposits on the books of CommBank, Westpac, NAB, and ANZ are equivalent to more than 70% of the total cash deposits in all authorised deposit-taking institutions (ADIs) in the country. 

Household deposits include savings accounts, term deposits, transaction accounts, and other types of cash deposits. 

The four major banks each offer a range of savings account options suitable for different needs and financial goals. However, just because they are popular, doesn’t necessarily make them the best for your needs.

Since their products generally feature similar interest rates and functionalities, the choice mostly boils down to the one that best aligns with your personal savings strategy and other priorities.   

Comparing bonus interest rates

When selecting a savings account, it’s crucial to compare the base variable rate to identify which offers the best potential return on your deposited funds. You can also maximise the introductory rates available to new customers for the first few months of opening an account. 

All Big Four banks offer savings accounts that pay bonus interest rates when specific conditions are met, e.g. reaching a savings milestone. That said, choosing a savings account that matches your ability to fulfil these criteria can significantly boost your interest earnings and ensure robust returns.

Here’s a quick overview of the conditions for the added interest rates available on the savings account products offered by Australia’s four major banks. 

These are correct at the time of writing and are subject to change.

Accessing money through ATM networks and digital platforms 

Despite banks closing branches nationwide amid the growing popularity of digital banking and cashless transactions, the Big Four continues to maintain a significant presence. They support their customers through a huge network of branches, ATMs, call centres, and digital banking platforms. 

CommBank has more than 700 branches across the CBA Group and a huge ATM fleet of nearly 2,000 deployed nationwide. That includes ATMs from its subsidiary Bankwest, of which it’s in the process of rebranding most of its branches as CommBank in Western Australia. While that’s already extensive, that is still not Australia’s biggest ATM network.  

NAB operates about 1,000 ATMs nationwide, but through its partnership with RediATM network and Australia Post, the major bank’s customers get access to more than 6,000 locations and ATMs nationwide. 

Westpac and its subsidiaries St George Bank, Bank of Melbourne, and BankSA have a shared network of approximately 3,000 ATMs across the country. Through the Westpac Global ATM alliance, the bank boasts the largest overseas ATM network, with over 50,000 machines customers can access for free.

ANZ likewise maintains a sizeable fleet of over 2,000 ATMs across the country, while its branches offer specialised in-person banking services such as detailed personal and business consultations and smart ATMs that feature enhanced self-service banking functions.

Whether you choose any of the four banks, you have access to their 24-hour customer support and online and mobile banking platforms. Each bank has its own mobile app that provides a range of services such as account management, money transfers, and bills payment, among others. 

Stashing money in term deposits

Australia’s four major banks also offer term deposit products to customers who prefer locking their funds for a fixed term in exchange for better returns. Their term deposit rates are generally comparable, reflecting the tight competition among these leading institutions, however tend to trail the market leaders and smaller, challenger banks' products.

Their rates can vary slightly depending on term length and any ongoing promotions. CommBank, Westpac, NAB, and ANZ offer short- to long-term deposits, ranging from one month to five years. If you’re looking to stash your funds in a term deposit, it’s advisable to review the latest offers directly from the banks’ websites to ensure you’re getting the best rate available at the time of investment.

Which Big Four bank offers the best home loan product?

The four major banks hold the largest share of total home loans written for both owner-occupiers and investors in Australia. 

Source: APRA, February 2024

Each of Australia's big four banks offers a broad range of mortgage products, featuring both fixed and variable rates, as well as options for principal and interest (P&I) or interest-only (IO) payments. Redraw facilities and the flexibility to make additional repayments are widely available, though specific terms and availability can vary by lender and loan type. 

While the home loan rates offered by CommBank, Westpac, NAB, and ANZ are generally competitive within the market, they may not always be the lowest. Smaller and non-bank lenders as well as fully digital banks which may have lower overhead costs often offer more attractive rates by passing these savings onto customers.

Nevertheless, the Big Four banks provide comprehensive customer service networks and can offer package deals that might be attractive to customers who prefer to consolidate their financial products with one institution, e.g. a loan that comes with a choice of credit card and/or transaction accounts. 

Big Four Bank Home Loans Compared: A Quick Glance

Here’s a guide to the home loan products available at Australia’s four major lenders.

These are correct at the time of writing and are subject to change.

Choosing among these banks depends on your personal preferences or financial circumstances, such as the desire for branch access, specific loan features, or the attractiveness of package deals relative to overall costs.

Big Four Bank Home Loan Approval Times

InfoChoice Group reached out to the major banks between 2021 and 2023 and asked for clarity as to the speediness of its home loan approval times. Only Westpac declined to comment.

Approval times are highly variable, however, and fast times are subject to a borrower having a simple application and all the right documentation.

Does the Big Four offer personal loans and car loans?

Each of the four majors provides options for both secured and unsecured personal loans catering to various borrowing needs. Loan amounts can range between $4,000 and $50,000, with terms up to seven years. Interest rates offered by the four institutions are comparable, typically ranging from competitive to high, depending on the loan type, the borrower’s creditworthiness, and in some cases, the purpose of the loan, i.e. sustainable or ‘green’ purchases may attract lower rates. 

CommBank, Westpac, NAB, and ANZ also offer loans to finance the purchase of new or used cars. Similarly, car loan terms available at these banks generally range from one to seven years and interest rates depend on whether there is a security or none. Repayment options are flexible.  

All four banks offer the ability to apply online, and applicants are usually required to provide proof of income, financial statements, and personal identification.  

Are Australia’s Big Four banks safe?

Australian banks are known globally as among the safest and most stable financial institutions – a reputation built on decades of rigorous regulatory reforms, stringent lending protocols, and effective risk management. 

The country’s banking sector is regulated to ensure that banks maintain high capital reserves to absorb any unexpected shocks like the global financial crisis (GFC) in 2008. The four majors, being well-capitalised, have a strong buffer to absorb potential losses during economic downturns. In fact, they well exceed the 4.5% requirement indicating adequate capital reserves as measured by the Common Equity Tier 1 (CET1), explained in further detail here. 

Further, under the Financial Claims Scheme, cash deposits in the Big Four – and all ADIs – are guaranteed by the federal government up to $250,000 per account holder. 

Say you deposit $250,000 with NAB, this guarantee ensures you’ll get all your money back in the unlikely event it folds. Essentially this is aimed at boosting depositor confidence and lessening the likelihood of a bank run, which happens when customers pull out their money simultaneously over solvency concerns. 

Additionally, all four banks have demonstrated resilience during financial crises and have scored high among credit rating agencies Moody’s, Standard and Poor’s (S&P), and Fitch. 

Current as of 2023

The Big Four have identical ratings indicating that all of them have low credit risk.

CommBank, Westpac, NAB, and ANZ are known for their robust financial services and are a common choice for Australians due to their extensive service networks and wide range of offerings. 

At the end of the day, with such comparable products and rates, the decision on which bank to park your money in or take out a loan depends on your situation and what you value the most. You may choose the bank with more responsive customer service or the one with a more user-friendly mobile app. Your proximity to bank branches and the availability of ATMs in your location can also be a deciding factor. The choice is yours, and you’re free to choose which bank is the best for you.  

Read more: Big 4 Home Loan Basics Car Loan Basics Term Deposit Basics Savings Accounts Basics Everyday Banking Personal Loan Basics

Bernadette Lunas

Finance Journalist

Bernadette is a journalist with years of experience covering topics in macroeconomics, real estate, and lifestyle beats for notable print media organisations. She joined the InfoChoice Group in 2024, bringing her passion for writing stories that help Australians make better decisions about money.

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