Britain's banks are facing a major clampdown on the commission payments that have been blamed for fuelling recent mis-selling scandals.
The Financial Services Authority (FSA) said it will look to introduce new rules if the sector does not address the use of incentive schemes, which it said were driving staff to mis-sell products to receive a bonus.
With the industry already paying out £9 billion in redress to customers mis-sold payment protection insurance (PPI), the regulator said a review of incentive schemes at 22 banks, building societies, insurers and investment firms had uncovered a range of serious failings.
One firm has been referred to the FSA's enforcement arm for further action while others have begun checking past sales to see if mis-selling has occurred and if they need to pay compensation.
The regulator said practices included a "first past the post" system where the first 21 sales staff to reach a target could earn a "super bonus" of £10,000.
And it found that basic salaries for sales staff at one firm could move up or down by more than £10,000 per year, depending on how much they sold.
Another firm excessively incentivised one product over another - despite claiming to offer impartial advice - meaning there was a clear risk that its advisers would sell the product that earned them more money.
FSA managing director Martin Wheatley, who will become chief of the Financial Conduct Authority when it takes control of financial regulation next year, said: "What we found is not pretty. Most of the incentive schemes we looked at were likely to drive people to mis-sell in order to meet targets and receive a bonus, and these risks were not being properly managed."
In a speech to senior bankers, compliance officers and trade groups, Mr Wheatley said cultural change was needed and chief executives were ultimately accountable for the way their staff are incentivised.
He said: "We, as the regulator, intend to change this culture of viewing customers simply as sales targets and I am going to be personally involved in getting this right."