Barclays has been fined £7.7 million for investment advice shortcomings, with customers potentially able to claim back a portion of £60 million in compensation.
The Financial Services Authority (FSA) charged the business for "a number of serious failings" in the way people were sold funds.
According to the FSA, Barclays did not ensure investments were suitable for individuals' aims and monetary standing or train staff members adequately to provide guidance.
It was also revealed that the firm had isolated poor selling practices after its own investigations, but neglected to address the problem.
Margaret Cole, the FSA's managing director of enforcement and financial crime, said: "Given Barclays' position as one of the UK's major retail banks, we view these breaches as particularly serious and fully deserving of what is a very substantial fine."
This news followed a recent £2.8 million FSA charge given to Royal Bank of Scotland and NatWest after they were deemed to have fallen short in dealing effectively with customer complaints.
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