UK online casinos operate under strict rules from the UK Gambling Commission,...

https://www.pfdbookmark.win/uk-online-casinos-operate-under-strict-rules-set-by-the-uk-gambling-commission-3

UK online casinos operate under strict rules from the UK Gambling Commission, which set limits on payout percentages and fairness. Many games offer around a 96% return to player (RTP), meaning the house keeps a margin