It’s possible that I’ll have a large capital gains tax (CGT) liability in this tax year. I’m a basic-rate taxpayer and have quite a bit of savings interest, which I'm worried will be taxed. What rate of CGT will I pay, and will the gain reduce my tax-free personal savings allowance? money expert, says…To recap: your personal savings allowance is the amount of savings interest you can earn each year without paying tax: it's £1,000 for basic-rate taxpayers and £500 for higher-rate taxpayers. The good news is that your personal savings allowance won’t be affected.