Does tax automatically taken out when i sell stocks in uk or do i need to pay through elsewhere
taxes are your responsibility to report and pay to HMRC. these are not done as part of your actions on the platform. HMRC provide a form you can use to submit to them I believe, but I haven’t needed to declare any myself so don’t have the link on hand.
There are many useful posts about this already on the forum. Also read here
If you have the S&S ISA you won’t need to declare anything. The only thing you pay is stamp duty tax and that’s done through the app when buying a stock.