UK betting companies paid out £19.6m in penalties in the last financial year for failing to protect problem gamblers and stop money laundering.
Online casino company Daub Alderney was ordered to pay £7.1m by the Gambling Commission, while Paddy Power Betfair – now known as Flutter Entertainment – was fined £2.2m.
The industry regulator ordered Casumo to pay a penalty package of £5.85m, while Videoslots was to pay £1m in lieu of a financial penalty.
InTouch Games Limited was asked to pay £2.2m, Betit Operations Limited was levied £1.4m, and MT Secure Trade was ordered to pay £700,000 in lieu of financial penalties.
The betting watchdog said it had carried out more than 160 investigations in 2018-19.
The Gambling Commission’s second annual enforcement report said a number of companies had failed to detect customers at risk of becoming problem gamblers.
It also found repeated examples of customers being allowed to gamble significant sums of money in short time frames, beyond their personal affordability and without any intervention from the operator.
Gambling Commission chief executive Neil McArthur said: “I want gambling consumers in Britain to be able to enjoy the fairest and safest gambling in the world and I want gambling operators to work with us to put customer enjoyment and safety at the top of their corporate agenda.
“As the report shows, we will be tough when we find operators bending the rules or failing to meet our expectations, but we also want to try and minimise the need for such action by providing advice, a programme of support material and compliance activity to help operators get things right in the first place.”
The report said a “substantial number” of investigations had been carried out in the online gambling sector last year, and added that some operators were found to have anti-money laundering policies that were not fit for purpose.
Earlier this year, betting firms, health bodies and charities said they would unite for the first time under a three-year strategy to make “much faster” progress with cutting gambling-related harm.
The National Strategy to Reduce Gambling Harms will co-ordinate work to tackle the problems and achieve a lasting impact, the Gambling Commission said.
Under the strategy, Public Health England will release its first review of evidence on health harms relating to gambling in spring next year.