Crypto Tax UK: Complete HMRC Guide for 2026

HMRC has been clear on cryptocurrency taxation since 2018, and the rules have only got stricter since. UK exchanges now share customer data with HMRC under mandatory reporting requirements introduced in January 2026. If you have been ignoring your crypto taxes, the window for that is closing fast.

How HMRC Classifies Cryptocurrency

HMRC does not treat cryptocurrency as currency. It treats it as a capital asset, like shares or property. This means disposals — selling, exchanging, gifting, or using crypto to buy goods — trigger Capital Gains Tax, not income tax. The distinction matters because CGT rates and reporting rules differ from income tax rules.

There are two categories that attract income tax instead of CGT: mining rewards and staking income. If you mine cryptocurrency and receive rewards, HMRC treats the fair market value at the time of receipt as income. The same applies to staking rewards — the value of tokens received is taxable as miscellaneous income in the year you receive them. You still owe CGT on any gain when you later dispose of those tokens.

What Counts as a Taxable Disposal

A disposal is triggered when you: sell crypto for fiat currency, exchange one cryptocurrency for another, use crypto to pay for goods or services, or gift crypto to anyone other than your spouse or civil partner. Each of these events creates a capital gain or loss that must be calculated and reported.

Notably, buying cryptocurrency with GBP is not a disposal and creates no tax liability. Holding cryptocurrency — even if its value increases dramatically — also creates no liability until you dispose of it. The tax event is the disposal, not the gain in value.

Calculating Your Gain or Loss

HMRC uses a specific method called the Section 104 pool for calculating the cost basis of cryptocurrency. Under this method, you maintain a pooled average cost for all holdings of each cryptocurrency. When you dispose of some, you apply the average pool cost, not the cost of specific tokens.

There are two exceptions that override the pool calculation. The same-day rule: if you buy and sell the same cryptocurrency on the same day, those transactions are matched against each other first. The 30-day rule: if you sell and then buy the same cryptocurrency within 30 days, the purchase is matched against the sale first. These rules prevent bed-and-breakfasting — selling to crystallise a loss and immediately repurchasing.

The Annual Exempt Amount in 2026

The Annual Exempt Amount for 2025/26 is £3,000. This means the first £3,000 of capital gains each tax year is tax-free. Gains above this threshold are taxed at 18% for basic rate taxpayers or 24% for higher rate taxpayers on residential property, but 10% for basic rate and 20% for higher rate on other assets including crypto.

The exempt amount was £12,300 as recently as 2022/23 and was cut sharply to £6,000 then £3,000 in subsequent years. The reduction has made tax reporting essential for many UK crypto holders who previously fell under the threshold.

Reporting Requirements and Deadlines

If your total gains exceed £3,000 in a tax year, or if you disposed of crypto worth more than £50,000 in total (even if your net gain is below the exempt amount), you must complete a Self Assessment tax return. The deadline for paper returns is 31 October following the end of the tax year. Online returns must be filed by 31 January.

For the 2025/26 tax year (ending 5 April 2026), the online filing deadline is 31 January 2027. Interest accrues on unpaid tax from 31 January 2027, and penalties begin at 30 days late. HMRC issued over 5,000 crypto-specific penalties to UK individuals in the 2024/25 tax year.

Record-Keeping Obligations

HMRC requires you to keep records of all cryptocurrency transactions for at least five years. Records needed include: the date and type of transaction, the value in GBP at the time, the amount and type of cryptocurrency involved, and the wallets or exchanges used. Exchange transaction histories and CSV exports from portfolio tracking tools like Koinly, CoinTracker, or Accointing satisfy this requirement if they contain the necessary fields.

If you used DeFi protocols, participated in liquidity pools, or received airdropped tokens, the record-keeping requirements are more complex. Each interaction with a DeFi protocol may constitute a disposal. HMRC published specific DeFi guidance in 2023 that covers liquidity provision and lending transactions.

What This Means for You

HMRC has the tools to find unreported crypto gains: exchange data sharing, blockchain analytics, and random enquiries into Self Assessment returns. The cost of getting caught — unpaid tax plus interest plus penalties up to 100% of tax owed — far exceeds the cost of filing correctly. If you have never reported crypto gains and think you may have exceeded the exempt amount in any past tax year, an accountant who specialises in crypto can help you make a voluntary disclosure, which typically results in lower penalties than being caught.

This article is for educational purposes only and does not constitute financial advice. Cryptocurrency investments involve significant risk. Always do your own research.