Good UK slot sites meet UKGC rules as a baseline, but that alone is not enough....

https://www.bookmarks4all.win/a-ukgc-licence-is-the-baseline-check-rtp-is-shown-cashouts-have-clear

Good UK slot sites meet UKGC rules as a baseline, but that alone is not enough. Check clear RTP data, how fast cash-outs are paid, and whether useful tools let you set limits, take a break or get help when play stops being fun.