Bolingford said the remediation was across a range of products and services and it was now conducting more analysis to drill into it further.
"A lot of what we are seeing is stuff was set up and then it didn't work properly. It's manual processing which comes up over and over again where systems haven't been changed or frontline customer services teams have to enter data into a number of places or spreadsheets and it's systems not talking to each other or not picking up on the issue."
She said it was only when firms had gone in and done a proper job of looking back to check whether things were working as they should be that issues had been picked up.
"There's quite a big job now going on in those firms to do those system fixes. We know that some of the work has been done but actually, it is taking them some time to put in the controls to make sure these things don't happen in the future."
The FMA has already taken legal action against AIA, Cigna, ANZ and Kiwibank over a range of product issues.
But Bolingford said all of the firms had issues.
"I can't think of any of the major institutions that haven't had remediation programmes in place."
She said a key message to the industry was that the checks and processes needed to be set up first before products were sold to the public.
"If you are putting products out there, don't put it out and then think about the controls."
More remediation was expected with only a third of the life insurance issues fully assessed to date.
"The scale of what we are seeing coming out here, we know this is not the end of the story. There is still work to be done and I expect there are some firms that haven't done as good a job as other firms."
Bolingford acknowledged the work by banks and insurers to date to fix their customer issues.
"We note that over the past 12 months, boards have displayed a greater understanding of what needs to occur to achieve consistent fair customer treatment."
She said there was likely to be more self-reporting to come as firms continued to look at their businesses.
"The more firms have looked, the more problems they've found. You can reasonably expect our future monitoring activities to consider how well firms have completed, and reported on, these matters," she said.
Bolingford said the work helped the FMA deepen its understanding of the banking and insurance sectors and enabled improved engagement with the industry in seeking to root out conduct problems and prioritise the interests of customers.
The regulator plans to use those lessons in a new conduct licensing regime for the finance sector which will begin in July next year.
The FMA wanted to help implement a new Conduct of Financial Institutions Regime in shaping conduct principles and practices, and prepare for licensing from next year.
It said firms would then be in a better position to demonstrate how they were treating customers fairly through fair conduct programmes.
The FMA and the Reserve Bank jointly undertook conduct and culture reviews of the banking and insurance sectors in 2018 and 2019 and found "significant weaknesses" in the way New Zealand banks govern and manage conduct risks.
The local reviews followed Australia's Royal Commission into the financial sector.
New Zealand Bankers' Association chief executive Roger Beaumont said the banking conduct and culture review four years ago found no systemic issues.
"But it did find that banks needed to do more to ensure they continued to do the right thing by their customers.
"In that time, as the FMA says, banks have worked hard to improve their internal conduct processes and proactively identify any issues and remediate them. Banks are also highly engaged in the new conduct regulation for financial institutions being developed by the government.
"Banks take their compliance obligations very seriously and are keen to ensure the new conduct regulation works well," he added.
