Paying tax on stock income

Uriziel

I have now made more than £3k from buying and selling stocks and am now thinking about how to pay tax on this.

1. I assume I would pay tax on this when I do a self assessment next year after the current tax year has ended. I don't need to buy tax right now. Is this right?
2. If I buy stocks now and make a loss, I can set my profits off and might not need to pay tax at all if overall I make a loss, right?
3. Where on the Trade212 app can I check to get the figure that I would need to use for tax reasons? In the settings in the transactions tab I can see a figure at the top saying "realised profit". Is this what I would need? Does this figure already include my "losses"?

phlebas192

1. Assuming that your gains are in the current 2025-6 tax year then yes. If you already need to complete a SA for other reasons then select the option to report capital gains in the tailor your return options. If you aren't completing a SA for other purposes then either register to do so before then end of October 2026 or otherwise I think you can use the real time reporting service [I tried this once and, unless it has improved a lot since then, it is easier to complete a SA].

If you complete your SA before the end of Dec 2026 and the total tax due is less than (I think) £3k then it will be recovered via a change in your tax code rather than needing to pay it in a liump sum.

2. Yes, losses made within the current tax year can be offset against current year gains. You can also offset losses made within the past 4 years (if not previously claimed) or anytime in the past if you have claimed them within 4 years and carried them forwards. Obviously it's better not to make a loss just to offset the taxable gains! nb: you don't need to have made a loss overall, just reduce them to below your £3k total gains allowance.