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

https://www.coast-bookmarks.win/uk-online-casinos-operate-under-strict-uk-gambling-commission-rules-designed-to

UK online casinos operate under strict rules set by the UK Gambling Commission to keep play fair and transparent. They often feature games with an average return to player (RTP) around 96%, showing the typical payout level