Before signing up, check the site’s licence on the UK Gambling Commission...

https://www.acid-bookmarks.win/before-joining-a-new-betting-site-verify-its-licence-on-the-uk-gambling

Before signing up, check the site’s licence on the UK Gambling Commission register and read bonus terms: licensed operators face a 10x wagering cap. Treat big offers sceptically, and check mobile usability and withdrawal times before depositing.