ASIC sues Commonwealth Bank over $8.5 million CommBiz fee overcharging

Australia's corporate regulator is suing Commonwealth Bank, alleging the country's largest bank overcharged roughly 42,000 business customers by about $8.5 million on its CommBiz platform.

The Australian Securities and Investments Commission filed civil penalty proceedings against CBA this week. The watchdog claims the bank misled CommBiz customers by failing to disclose fees tied to moving money out of their own CommBiz accounts.

ASIC says business customers were told about fees for transferring money to or from third-party accounts. But the bank allegedly didn't disclose other charges related to moving funds from the CommBiz account itself.

How long did the alleged overcharging run?

The overcharging allegedly stretched back 19 years, to the launch of the CommBiz platform in 2006. ASIC puts the affected window between November 2020 and May 31, 2025, covering approximately 42,000 CommBiz customers and around $8.5 million in excess fees.

ASIC commissioner Alan Kirkland accused the bank of failing its small business customers.

"Small businesses are busy enough," he said. "They should not have to scrutinise every transaction to make sure that their bank is charging them the right fees."

Kirkland added: "ASIC will continue to take action where banks don't have the systems and processes in place to deliver on the basic promises they make to their customers."

The regulator is seeking fines, orders and costs against the bank. A hearing date has not been set.

What has CommBank already done?

CommBank paused the disputed fees in June 2025. It amended its CommBiz terms of service two months later, in August, and will waive the relevant fees from February 2026.

The bank has already completed a remediation program reaching back to December 2006. That program returned $26.4 million to CommBiz customers, including some 40,000 small businesses.

CommBank said the fee at the centre of the proceedings was 25 cents, plus GST. The median repayment to customers was approximately $85, while the mean payment sat at roughly $442, including interest.

How did CBA respond to the lawsuit?

In a statement shared with investors on Thursday morning, CommBank acknowledged shortcomings in how it charged fees but disputed parts of ASIC's case.

"While CBA accepts that it did not get things right for CommBiz customers and apologises to all customers impacted by this matter, CBA does not accept the way that some allegations have been formulated," the bank said.

"It therefore expects to defend certain aspects of the claim, or otherwise continue to engage with ASIC to efficiently resolve the proceedings."

The bank also stressed its own role in surfacing the issue. It said it had "self-identified this matter, reported it to ASIC, and has cooperated fully with ASIC throughout its investigation".

"CBA has taken additional rectification steps to reduce the risk of similar incidents," the bank added.

What happens next?

The case now heads to court with no confirmed hearing date. CBA has signalled it will contest some allegations while leaving the door open to a negotiated resolution — a posture that could see the matter settle before trial. Either way, the $26.4 million already repaid and the February 2026 fee waiver mean the practical fallout for CommBiz customers is largely in place before a judge weighs in on the penalties.