Credit card insurer CPP has said it faces a bill of £15m after agreeing with the City watchdog to review its past sales.
The York-based group, which sold products aimed to protect people against identity theft, has been under investigation by the Financial Services Authority (FSA) since last March.
Now CPP has agreed to contact customers that it approached directly.
The firm will also overhaul its policy renewal process.
"CPP has agreed to implement with FSA oversight a number of changes to its renewals process, in order to highlight more clearly to customers that they have the right not to renew the product, and to explain clearly to the customer the advantages and limitations of the relevant product," the company said in a statement.
"CPP will now work with the FSA to agree the detail of these proposals."
The group estimated that compensation for customers, the potential loss of renewal business, and the review would cost it between £10m and £15m.
CPP's shares remain suspended while the discussions continue.