Australia’s largest mortgage lender cites ‘fraud being attempted through mortgage broking and referral channels’
Commonwealth Bank, the largest home loan provider in Australia, has reported itself to the authorities over a suspected $1 billion worth of fraudulently obtained home loans.
AFR reported that CBA proactively referred itself to the police and the corporate watchdog after a major review of compliance practices and customer lending documents revealed swatches of potentially doctored applications, including AI-generated submissions.
It comes at CBA, like the wider financial services industry, grapples with the onset of AI technologies. The bank is in the midst of rolling out AI systems across its business banking, communications and fraud-detection operations. In March 2025, CBA invested in AI firm Anthropic to drive AI adoption at the bank.
A CBA spokesperson said the wider home loan industry was facing “sustained and increasing levels of attempted fraud, driven by criminals who actively evolve their methods”.
They added: “This is an industry-wide challenge, with fraud being attempted through mortgage broking and referral channels.
“Like others, we have increased our focus on financial compliance, and we’re continually reviewing our policies and processes and making changes to help protect our customers, the bank, and the community.
“Last financial year CBA invested $900 million to help protect customers from fraud, scams, cyber threats, and financial crime.”
CBA reportedly received its first complaint through its SpeakUP whistleblower platform in February 2025. Additional complaints were made throughout the year before CBA informed the New South Wales police and regulators of potential issues with its loan book.
Last year, an alleged organised financial crime group called the Penthouse Syndicate reportedly defrauded another lending giant, NAB, of around $150 million. It has not been suggested that the Penthouse Syndicate is involved in the alleged $1 billion of fraudulent home loan applications at CBA.
In November 2025, CBA tightened its policy of accepting broker-introduced applications on behalf of companies and trusts. It is unclear if this decision was related to suspected fraud, as the move was part of a wider industry move to adjust its risk setting by limiting company and trust lending.
While ite scale of the potential fraud is large, CBA’s mortgage book is massive. As of 30 November 2025, its combined owner-occupier and investor housing portfolio totalled over $611 billion, representing around a quarter of all mortgages in Australia. Westpac is a distant second at less that $499 billion.
MPA has reached out to CBA for further comment.
