Consumers made more than 21,000 complaints to their bank in the three months to June 30 - new data made public for the first time today has revealed.
Up until now the Banking Ombudsman has only collected data on complaints and disputes handled by it directly - meaning only a fraction of the issues between banks and their customers has been publicly available.
But a new online dashboard will reveal how many complaints banks have directly received, in what areas and how long the bank takes on average to resolve issues.
And from February consumers will be able to compare how many complaints their bank gets and how well they handle those complaints compared to other banks.
Banking Ombudsman Nicola Sladden said the dashboard would provide for the first time an overview of the nature and extent of complaints and how banks responded.
"Until now, the scheme has been the only source of information about complaints, but our information has been incomplete because we deal with only complaints banks have been unable to resolve themselves."
To put it into perspective the Banking Ombudsman received 722 complaints in the three months to June 30 whereas the banks directly received 21,468 during the same period.
The June bank complaints figure was 9.3 per cent down on the previous three months.
The dashboard breaks down complaints by product and service type such as credit cards, investments, insurance and processing methods and underlying problems such as transaction error, faulty advice or information and unwarranted or excessive fees.
It also shows how long each type of complaint took to resolve and what the outcome was.
Complainants are profiled by age, gender, location and whether an individual, business or trust.
Sladden said the interactive dashboard would be updated quarterly to show trends and cumulative totals. Data on complaints about individual banks would begin appearing by February 2021.
The dashboard includes data from all major retail banks which captures 99 per cent of the banking sector. Two smaller international banks have yet to commit to providing data.
A complaint is defined as when a customer tells a bank that they are dissatisfied with the bank's product, service or staff, or the way the bank has handled a complaint. The customer must also expect a response or resolution.
Sladden said the dashboard had the support of regulators and banks who could use the data to improve their own services.
"It's a fact of life that when you deal with hundreds of thousands of customers and process millions of transactions each day, things will sometimes go wrong. The vital thing is to identify, correct and learn from these mistakes. The dashboard will help greatly with that effort.
"The other benefit is that it will enable customers to see how their bank's complaints and complaints-handling record compares with that of rivals."
Reserve Bank governor Adrian Orr said how banks respond to and learn from complaints said a lot about their culture and conduct.
"We expect the increased transparency provided by the dashboard will lead to better customer outcomes."
Rob Everett, chief executive of the Financial Markets Authority, said it was pleased to see the Banking Ombudsman launch this customer complaints dashboard.
"This shines a light on customer concerns and how banks are addressing them. These are important ingredients for ensuring customers are treated fairly."
The launch of the dashboard follows a conduct and culture review undertaken jointly by the Reserve Bank and the Financial Markets Authority in 2018 after Australia's royal commission into misconduct in the financial sector found widespread problems prompting calls for a commission to be held here.
The New Zealand review found there were "significant weaknesses" in the way New Zealand banks govern and manage conduct risks, and changes needed to be made.
The banks were given until March 2019 to come up with individual plans on how to address their shortcomings and remain under the close eye of the regulators.
Since then banks have ditched frontline sales incentives.