There are about 6,400 registered financial advisers currently in the market, who are required to register on the financial services providers register, be members of an external dispute resolution scheme and act with care, diligence and skill.

But beyond that they have few obligations.

Institute of Financial Advisers chief executive Fred Dodds said about 4,000 of those could be expected to be working in risk and mortgage advice.

"The FMA insurance replacement report said that there were 3,700 advisers who had more than one policy on the books and also in their report stated that in 2014 50% of them earned less than the minimum wage," he said.

"Now you could say that they are not advising but there will be a number who have mature books and spend the majority of their time servicing/advising on their in-force books but I suspect that there is another large number who are sitting on trails which also of course includes another anecdotal figure of around $1 billion - category one products - of FUM that RFAs continue to get renewal/trails on."

David Greenslade, of training provider Strategi, said he did not keep data but expected that about 20% of advisers might not be working full-time.

Russell Hutchinson, of Chatswood Consulting, said only about 200 advisers sold more than 100 policies a year each.

"There's a group of about 2,000 advisers that regularly use Quotemonster," he said. "In terms of being busy enough to do quotes."

He said it was fair to assume that about 2,500 were writing policies on a relatively regular basis. That means at least a couple of thousand are doing relatively little business. Depending on the requirements of the new regime, it may not be worth their time remaining in the industry.

Hutchinson said many of the people who were doing very little business could be happy to be nominated representatives for financial advice providers.

Some might not be advisers as most people would think of them, he said, but could be a bookkeeper or vehicle finance specialist who only needed RFA status from time to time.

He said it should be expected that there would be a drop in numbers when the new regime rolled out.

"The barrier to entry to be an RFA isn't very high. All you need to do is pay your fee and get a police check. There are lots of people who have only had to do that and have another connection with financial advice."

He said it was probably the intention of the rule changes that some would not remain in the industry

"We do not have any data on how many advisers are part or fulltime," a spokesman for the FMA said.

"In relation to life insurance, our report on replacement business published last year showed that of 3,700 advisers who had at least one active policy on their books, 31% had no more than nine policies, suggesting that there are certainly some advisers who have only small life insurance practices. However, as that exercise did not gather information about other products under advice, we can’t extrapolate from this finding to any more general conclusion."