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

https://www.kilobookmarks.win/uk-online-casinos-operate-under-strict-rules-from-the-uk-gambling-commission

UK online casinos operate under tight rules set by the UK Gambling Commission that aim to keep play fair and safe. Despite limits like a minimum 96% return to player rate, these sites find ways to earn through game margins and fees