How does tax work in the UK? Do we just withdraw our funds and then pay tax or does it have to be sorted out before withdrawing?
Good question. I dont think you can get away with not paying taxes in a strict country like the UK, I advise you to keep a record of your transactions and consult a professional for advice so you dont get into trouble and end up paying more than you bargained for. I found this article on the internet, they give a good assessment of how bitcoin is taxed. You can use their calculator to see how much you could be taxed for crypto gains.
In the UK, you have to pay tax on profits over £12,300. And so irrespective of your view on the validity of cryptocurrency, you will always be liable to pay tax on your investment profits from them.