Crypto’s tax trail is longer than you think

A common assumption is that crypto is only taxed when you cash out to pounds. That is not how HMRC sees it. In the UK, selling a token, swapping it for a different token, spending it or giving it away can all count as a disposal for Capital Gains Tax. The pound never has to touch your bank account.

For people who have spent years moving between coins on an exchange, that can mean a long list of taxable events they never thought of as sales. Many only find out when HMRC writes to them. This piece sets out how the rules work, what the tax return now asks, and why the trail is getting easier for HMRC to follow.

The swap is the sale

HMRC’s guidance lists four ways you dispose of cryptoassets: selling them for money, exchanging them for a different type of cryptoasset, using them to pay for goods or services, and giving them away. The one exception for gifts is a gift to your spouse, civil partner or a charity.

So if you swap bitcoin for ether, HMRC treats that as disposing of the bitcoin. You work out its value in pounds at the time of the swap, compare it with what the bitcoin cost you, and the difference is a gain or a loss. The same applies if you buy something with tokens. It does not matter that you still hold crypto afterwards.

Receiving tokens can be taxable too, but under different rules. HMRC says tokens received from mining, staking, lending or liquidity pools, or as payment from an employer, are generally income. Income Tax is due on their value when you receive them. If you later sell them for more than that value, Capital Gains Tax may also apply to the increase.

You can owe tax on crypto without ever having had a single pound in your hand.

How the gain is worked out

You do not usually match each sale to a specific coin you bought. Instead, HMRC requires a “pool” for each type of token. Every time you buy or receive tokens of that type, you add what you paid to the pool. When you dispose of some, you deduct a proportion of the pooled cost. Non-fungible tokens are the exception: each is treated separately.

There are two important exceptions, borrowed from the rules for shares. If you buy and sell the same token on the same day, those trades are matched against each other first. If you sell tokens and buy the same type back within 30 days, the new purchase is matched to the earlier sale rather than going into the pool. This stops people selling at a loss and buying straight back just to create a tax loss.

From the proceeds you can deduct allowable costs. HMRC’s list includes transaction fees and the cost of a valuation to work out your gain, as well as your share of the pooled cost. You cannot deduct mining costs such as equipment or electricity.

Everyone has a Capital Gains Tax allowance, currently £3,000 a year. Gains above that are taxed at 24% for higher and additional rate taxpayers. Basic rate taxpayers pay 18% on the part of the gain that fits within their remaining basic rate band, and 24% on the rest. Losses can reduce your gains, but HMRC says you must report them first.

If you have lost access to a wallet, HMRC does not treat a lost private key as a disposal. Where there is no prospect of recovering the tokens, you may be able to make a negligible value claim, which can let you record a loss.

What the tax return now asks

If your total gains for the tax year, which runs from 6 April to 5 April, are above the allowance, you must report them. You can do this on a Self Assessment return or through HMRC’s real time Capital Gains Tax service. From the 2024 to 2025 tax year onwards, the Self Assessment return has its own cryptoasset section, completed in pounds.

The deadlines are fixed. If you need a return for the first time, you must tell HMRC by 5 October after the end of the tax year. For the 2025 to 2026 tax year, the online return and any tax owed are both due by 31 January 2027. Miss the filing deadline and there is an initial £100 penalty, with more after three, six and twelve months, plus interest on anything paid late.

The trail is getting shorter

Since 1 January 2026, cryptoasset exchanges and other service providers operating in the UK have had to collect and record set details about their customers under the Cryptoasset Reporting Framework. That includes name, date of birth, home address, country of residence and a tax reference such as a National Insurance number, alongside the value, type and number of units in each transaction.

This is an international scheme, but the UK has extended it to cover UK-resident customers, not just overseas ones. In practice, that means HMRC will receive annual information about what UK users of these platforms have been buying, selling and swapping. HMRC also says a customer who fails to give the required information to their provider may face a penalty, and the provider may refuse to keep serving them.

None of this changes what tax is owed. It changes how easily a gap between what you reported and what your exchange reported can be spotted.

Records worth keeping

HMRC is clear that you must keep your own records. Exchange statements may not be enough, because they will not usually track your pooled costs across every platform and wallet you use. For each type of token, keep:

• The type of token, and the date of every purchase, sale, swap, spend and gift.
• How many tokens you disposed of each time, and how many you had left.
• The value in pounds at the time of each transaction.
• Fees paid on each transaction.
• Your pooled cost before and after each disposal.
• Bank statements showing money moving to and from exchanges.
• Transfers between your own wallets, so they are not mistaken for disposals.
• Records of any tokens received from staking, mining, lending or airdrops, with their value in pounds when received.

Export your transaction history from every exchange you have used while you still can. Platforms close, change hands or delete old accounts, and rebuilding years of trades from memory is slow and unreliable.

If you think you are behind

If you owe tax from earlier years, HMRC runs a Cryptoasset Disclosure Service for exactly this. You work out what you owe, submit the disclosure online, and then pay. HMRC says you will get a payment reference within 15 working days and should pay within 30 days of submitting.

How far back you need to go depends on why the tax was missed. HMRC’s guidance says up to 4 years if you took reasonable care, up to 6 years if you were careless, and up to 20 years if the underpayment was deliberate. HMRC also warns that if you do not come forward, you could face extra interest and penalties. In general, telling HMRC yourself puts you in a better position than waiting to be asked.

For anything complicated, such as many years of trading, decentralised finance, or tokens received as income, a qualified tax adviser is worth the cost. This article explains the rules in general terms. It is not personal tax advice.

This article is for general information and is not medical, legal or financial advice. Laws differ between countries. Read our editorial standards.