What happens if I miss the Self Assessment deadline?

From 1 February, HMRC applies a £100 fixed penalty, even if you owe no tax. Interest starts on unpaid tax. After three months, daily penalties can apply, and further late payment penalties are charged at 30 days, six months, and twelve months. File the tax return first, then arrange Time to Pay if needed.

Do I need to report crypto if I made no profit?

You must complete CGT pages if your total disposal proceeds exceed four times the annual allowance, £12,000 for 2024 to 2025, even if gains are within the £3,000 allowance. Also report any taxable crypto income from staking, airdrops, or rewards. Keep accurate dates, values in pounds, and fees for each transaction.

How do payments on account work for Self Assessment?

If most of your tax is not collected through PAYE, you usually make two advance payments, each 50 percent of last year’s bill. They are due on 31 January and 31 July. If your current year income is lower, you can claim to reduce them, but interest may apply if you cut them too far.

What records should investors keep for CGT and crypto?

Keep transaction dates, quantities, prices in pounds, and fees. For crypto, maintain wallet and exchange CSVs, same day and 30 day matches, and pooled cost. For shares and funds, track contract notes and dividend statements. Store ISA statements separately, as gains inside ISAs are not reportable on your tax return.

Global Market Insights

UK Tax Return Rush January 26: HMRC £100 Fines Loom, Crypto/CGT Traps

ByDanny Kontos January 26, 2026January 26, 2026

The tax return deadline is 31 January, and late filers face an automatic HMRC £100 fine plus interest. Investors and crypto traders need to check capital gains, dividends, and payments on account before month end. New CGT rules and a specific crypto section raise error risks. We explain what to file, how penalties build, and how to plan cash without forced selling. Act now to file your tax return and keep your portfolio on track.