Australia's major banks face a public grilling over cases where they have engaged in inappropriate or unsuitable lending for mortgages, cars and credit cards.
A public hearing begins in Melbourne on Tuesday as the financial services royal commission tries to find out why the problems happened.
National Australia Bank, Commonwealth Bank, Westpac and ANZ all feature in a list of case studies to be covered by the inquiry, which will also examine the banks' arrangements with their intermediaries.
The cases have already been addressed by the banks and the Australian Securities and Investments Commission, often resulting in fines and refunds to customers.
The royal commission will use the cases to find out why the conduct occurred and what was and should have been the response.
Consumer Action Law Centre CEO Gerard Brody said the aim was to understand the drivers and causes of the conduct inside banks and financial institutions.
"Being a public forum there can be more transparency and perhaps accountability about what really caused the misconduct, and that's what we expect will be uncovered over the next couple of weeks," he said.
Mr Brody acknowledged the banks had made improvements in some areas but said the actual causes and drivers of many problems had not been resolved.
"The culture inside the banks to sell is strong, rather than them really considering whether this is the appropriate product for the customer and providing them with good customer service throughout."
The commission will hear evidence that consumers have not always been treated honestly and fairly in Australia's $1.6 trillion home loan market, senior counsel assisting the inquiry Rowena Orr QC told its opening hearing last month.
Some of the events may have involved breaches of the law and others departures from community standards and expectations, she said.
Ms Orr said the commission's inquiries also revealed car lending practices that appeared to depart from the standards that consumers be treated honestly and fairly.