Check each site on the UK Gambling Commission register. Read bonus terms...

https://ace-wiki.win/index.php/If_a_site_has_an_overseas_licence,_can_it_serve_Great_Britain%3F

Check each site on the UK Gambling Commission register. Read bonus terms closely: don’t assume a 10x wagering cap applies to licensed operators. Test mobile usability and check withdrawal methods and times; headline offers aren’t the whole story.