When choosing a UK casino with many high RTP slots, start by checking the game...

https://gregorysbestchat.bearsfanteamshop.com/how-do-i-check-if-a-casino-feels-transparent-about-gambling-risks

When choosing a UK casino with many high RTP slots, start by checking the game library size and variety of software providers. RTP is a theoretical return, so use it as a guide, not a guarantee