National Australia Bank

Overview

National Australia Bank (NAB) is one of Australia’s Big Four banks, a Melbourne-based group formed from the merger of the National Bank of Australasia and the Commercial Banking Company of Sydney, and today Australia’s largest business lender despite ranking only third among the four by total assets. (Savings.com.au) (BankingDay) Its history runs from a Melbourne opening on 4 October 1858 to a group spanning business and personal banking, a New Zealand subsidiary, and a digital bank built from a neobank acquisition. (InvestSMART) Its recent story is one of simplification under Ross McEwan, continued by successor Andrew Irvine, alongside an anti-money laundering remediation only closed by regulators in July 2025. (BankingDay) (Australian Broker)

From colonial predecessors to a Big Four bank

The National Bank of Australasia first opened for business at 8am on 4 October 1858 in Melbourne, with capital of 90,000 pounds. (InvestSMART) It grew by absorbing smaller banks, including the Colonial Bank of Australasia in 1918 and the original Bank of Queensland in 1922. (InvestSMART) Its merger partner was older still: the Commercial Banking Company of Sydney had been established in 1834. (InvestSMART) InvestSMART dates their merger to 1981; the modern bank later added the Bank of New Zealand in 1992 and took over MLC in 2000. (InvestSMART) The bank’s Melbourne base endured through these changes. (InvestSMART)

With Commonwealth Bank, Westpac and ANZ, NAB forms the Big Four, together holding about $4.20 trillion in residents’ assets, roughly 70% of the market. (Savings.com.au) On the Australian Prudential Regulation Authority’s August 2026 figures, NAB ranked third with $992.49 billion in total residents’ assets, behind Commonwealth Bank at $1.26 trillion and Westpac at $1.16 trillion. (Savings.com.au) By market capitalisation, however, it ranked second at $118.12 billion as of 2 October 2026, just ahead of Westpac. (Savings.com.au)

Big Four measure, 2026	NAB	Rank
Total residents’ assets, August 2026	$992.49 billion	3rd
Market capitalisation, 2 October 2026	$118.12 billion	2nd
Business loans, June 2026	$275 billion	1st

Australia’s business bank, and a digital second act

The ranking that sets NAB apart is business lending. (BankingDay) On APRA data to the end of June 2026, NAB remained the largest business lender, with $275 billion in loans to non-financial businesses against Commonwealth Bank’s $245 billion, and the two banks together accounted for 41% of all business lending by banks. (BankingDay) Commonwealth Bank led instead on business deposits, at $207 billion against NAB’s $191 billion. (BankingDay)

NAB has pursued growth at the other end of the market through digital banking. (FinTech Futures) Its A$220 million acquisition of Sydney digital bank 86 400 received Federal Court approval in May 2021, the final clearance after Australian Competition and Consumer Commission approval the previous month, and 86 400 was combined with NAB’s digital offshoot UBank. (FinTech Futures) NAB already held an 18.3% stake, and at acquisition 86 400 had about 85,000 customers and 320,000 accounts. (FinTech Futures) A year later, NAB completed its A$1.2 billion purchase of Citigroup’s Australian consumer business, including 800 Citi employees. (The Asset) By 2024, ubank had around 800,000 customers. (BankingDay)

Scrutiny, remediation and a leadership handover

NAB’s modern reset began with a blunt internal diagnosis. (BankingDay) Ross McEwan’s 2020 strategy review found overly complex products, slow customer experiences, inconsistency and too much bureaucracy, and his remedy was simpler products and disciplined execution. (BankingDay) Andrew Irvine, who had led NAB’s business and private banking division since 2020 after more than 12 years at the Bank of Montreal, succeeded McEwan as group chief executive officer on 2 April 2024. (FinTech Futures) Five weeks into the job, Irvine said he would review McEwan’s strategy but that the market should not expect any major pivot. (BankingDay)

Running in parallel was a regulatory remediation that defined much of Irvine’s inheritance. (Financial Standard) After AUSTRAC identified concerns about NAB’s anti-money laundering program and formally investigated five reporting entities in June 2021, NAB accepted an enforceable undertaking in 2022 without a civil penalty, unlike Commonwealth Bank and Westpac, which had received large fines. (Financial Standard) The undertaking required a remedial plan covering customer identification, risk assessment, transaction monitoring, governance and assurance, with an independent auditor reporting annually. (Financial Standard) BankingDay reported the program cost around $100 million a year from 2021/22 and was still ongoing in 2024. (BankingDay) In July 2025 AUSTRAC finalised the undertaking after its independent auditor found NAB had satisfied the terms, but chief executive Brendan Thomas warned that closure “still doesn’t give the business a clean bill of health”. (Australian Broker) The auditor also made further recommendations on transaction monitoring and assurance frameworks, which NAB accepted. (Australian Broker)

What this profile does not claim

This profile does not resolve the 1981 versus 1982 dating question for the founding merger: it follows InvestSMART in dating the merger to 1981, while noting that other reference material dates the formal modern company to 1982. It does not assert current customer, branch or profit totals, unverified at the research date. It does not claim that the closure of the AUSTRAC undertaking ended NAB’s anti-money laundering obligations: AUSTRAC itself said further work remained and compliance must be sustained. Finally, it does not present NAB’s business-lending lead as leadership across all measures, since Commonwealth Bank led on business deposits in the same APRA data.