ANZ has been ordered to pay some customers $29.4 million after botching up interest calculations between May 2015 and 2016.
Around 86,000 accounts will be affected by the settlement announced today, ANZ says.
In 2018, the Australian-owned bank admitted an error in its loan calculation that it was misstating the amount of interest on loans.
It previously paid the impacted customers $6 million but today, the Commerce Commission confirmed a new settlement deal which sees an extra $29.4 million paid out.
ANZ will also admit in the High Court that it "engaged in conduct that breached its responsible lending obligations", the Commerce Commission says.
ANZ says it's worked with the Commerce Commission since 2017 on the issue.
"While we believe our initial payment to impacted customers was fair and better than overseas examples, after discussions with the Commission, we'll make a further payment to around 86,000 accounts to recognise that we didn't meet our lender responsibilities under… the Credit Contracts and Consumer Finance Act 2003," managing director of retail and business banking Ben Kelleher said in a statement today.
"ANZ is sorry this issue happened. We worked quickly to fix the problem, owned up to it, and we've made sure no customers are disadvantaged.
"We’ll begin to make the further payments to relevant customers over coming months."
Affected customers will be contacted directly by ANZ with a physical letter, the Commerce Commission says.