UK online casinos operate under strict rules set by the UK Gambling Commission...

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

UK online casinos operate under strict rules set by the UK Gambling Commission to ensure fairness and player protection. They often offer games with a minimum 96% return to player (RTP), meaning most bets are returned over time