Insurer Youi has been fined $100,000 by the Insurance Council for misleading sales practices.

It is the maximum financial penalty the council can impose and it has been warned any future misconduct will risk it being stripped of its membership.

In August, Youi pleaded guilty in the Auckland District Court to 15 representative charges brought against it by the Commerce Commission.

The charges included making misleading representations on its website over customers' ability to get a quote, telling clients they had to provide bank or credit card details and demanding payment or debiting consumers' bank or credit cards without their permission.

Council president Chris Black said the board considered terminating Youi's membership.

"ICNZ sets high industry standards for all members to follow and Youi's business conduct has fallen well short of this expectation," he said.

The board found Youi breached a council rule requiring members to conduct their business in accordance with the Fair Insurance Code and in a legal, honourable and proper manner.