High street lender Santander has been fined £12.4 million after the City watchdog uncovered "serious failings" in investment advice provided by the bank.
The Financial Conduct Authority (FCA) said Santander's advice was flawed after it found staff were not being trained properly and failed to get to grips with customers' personal circumstances and the level of risk they were prepared to take.
The bank also failed to ensure information was clear and did not make regular ongoing checks that investments were still suitable.
Santander said it has since closed its old bancassurance businesses and overhauled branch-based investment advice.
It will contact affected customers and compensate those left out of pocket, but the FCA said redress was likely to be minimal given that investment returns have been boosted by rising stock markets in recent years.