The review into the funding of the Financial Services Compensation Scheme will be published before Christmas.
Graeme McLean, the Financial Conduct Authority's head of banking, lending and distribution, said the regulator would set out how it's proposals would impact advisers' bills.
He was speaking at the Association of Professional Financial Advisers's financial professionals forum when he said the FCA had been thinking about the funding classes for the FSCS levy.
Mr McLean said: "We want to have funding classes which are sustainable.
"What we need to make sure us that the costs fall into classes which are fairly differentiated.
"You could break down each type of loss making business into a class but that would create unsustainable funding classes."
He added that there was a role for professional indemnity insurance.
Mr McLean added that a product levy had been a popular suggestion but the need for legislation to introduce one posed difficulties for its introduction.
He also pointed out that the benefits of a product often depend on someone's individual circumstances.
The FCA has said it will be considering the merits of a risk-based levy for products when it consults on its proposals for the funding of the FSCS.
Alex Kuczynski, the director of corporate affairs at the FSCS, agreed about the role of PI insurance as a "front stop" for claims.
He said: "There is not a general disquiet about the need for the scheme to exist.
"We would like to see, after this consultation, a model which we can live with and will endure for a few years and won't be reopened two or three years down the line."
He said a number of people had suggested the FSCS could borrow to make sure the levy remains flat.
But he said the "quite significant" costs of interest meant it had been ruled out.
The review into the FSCS levy was launched last year and the FCA has agreed it poses problems for advisers, particularly in relation to its unpredictability.
