Crypto Tax Calculator UK 2025

How Crypto Tax Works in the UK

HM Revenue and Customs treats cryptocurrency as property for tax purposes, not as currency or money. This means that when you dispose of a crypto asset at a profit, you are subject to Capital Gains Tax (CGT) on the gain, in much the same way as you would be if you sold shares or a second property. The tax is not levied on the total amount you receive; it applies only to the gain, which is the difference between what you paid for the crypto (the allowable cost) and what you received when you disposed of it (the proceeds).

Every individual has a Capital Gains Tax annual exempt amount, which for the 2025/26 tax year is £3,000. This exempt amount covers all your capital gains from all sources combined — shares, property, crypto, and anything else — not just your crypto gains in isolation. Once your total gains exceed £3,000, the excess is taxable. The rate of CGT you pay depends on your total taxable income: gains that fall within the basic rate band (up to £50,270 of total income for 2025/26) are taxed at 10%, while gains that push you above the basic rate threshold are taxed at 20%.

Unlike shares held within an ISA or pension, there is no tax wrapper available for cryptocurrency holdings. Every disposal is potentially a taxable event, and the onus is on you to keep accurate records of your purchase price, transaction fees, and disposal proceeds for each transaction. HMRC has been increasingly active in seeking information from crypto exchanges, and it is important to report your gains accurately and on time.

It is also worth noting that receiving cryptocurrency as income — for example, as payment for work, through mining, staking rewards, or airdrops — may be subject to Income Tax and National Insurance rather than Capital Gains Tax. The tax treatment depends on the nature of the activity and whether HMRC considers it to be a trade or a miscellaneous income source. If you receive crypto as income, its market value at the time you receive it becomes your allowable cost for any future CGT calculation when you eventually dispose of it.

What Counts as a Disposal

Not every crypto transaction is a taxable event. HMRC defines a disposal as any occasion when you cease to own a crypto asset. The most common types of disposal that trigger a Capital Gains Tax calculation are outlined below.

Selling Crypto for Pounds or Another Fiat Currency

The most straightforward disposal is selling your cryptocurrency on an exchange for sterling, euros, dollars, or any other traditional currency. Your gain is the sale proceeds minus your allowable cost (what you paid for the crypto, including any exchange or network fees at the time of purchase). If you sell at a loss, you can use that loss to offset other gains.

Swapping One Cryptocurrency for Another

Exchanging Bitcoin for Ethereum, or any crypto-to-crypto swap, is a disposal for CGT purposes. You are treated as having sold the first cryptocurrency at its market value at the time of the swap, and having purchased the second cryptocurrency at that same market value. This means you may owe tax on a gain even though you never converted to pounds. Many people overlook this, particularly if they are moving between tokens frequently. Each swap is a separate taxable event that must be recorded.

Spending Crypto on Goods or Services

Using cryptocurrency to buy anything — whether a cup of coffee, a car, or a subscription — is a disposal. The proceeds are the sterling value of whatever you purchased at the time of the transaction. If the crypto you spent has increased in value since you bought it, you will have a capital gain on the difference.

Giving Crypto Away

Giving cryptocurrency to someone as a gift is a disposal. You are treated as if you sold it at market value at the time of the gift, and you owe CGT on any gain. The one important exception is transfers between spouses and civil partners, which are treated as taking place at no gain and no loss — effectively a tax-free transfer. This spousal exemption can be a useful planning tool.

What Is Not a Disposal

Transferring crypto between your own wallets (for example, from an exchange to a hardware wallet) is not a disposal and does not trigger a CGT liability. Buying cryptocurrency with pounds or another fiat currency is also not a disposal of the crypto itself (though it may be a disposal of the fiat currency in certain unusual circumstances). Simply holding crypto, regardless of how much its value changes, does not create a taxable event.

Share Pooling and Cost Basis

If you have bought the same cryptocurrency at different times and prices, HMRC requires you to calculate your cost basis using a method called share pooling. Rather than tracking the cost of each individual token, you calculate a single average cost per token across all your purchases.

For example, if you bought 1 Bitcoin for £20,000 in January and another 1 Bitcoin for £30,000 in March, your pool contains 2 Bitcoin with a total cost of £50,000, giving an average cost per Bitcoin of £25,000. If you then sell 1 Bitcoin for £35,000, your gain is £10,000 (proceeds of £35,000 minus the average cost of £25,000), and your remaining pool contains 1 Bitcoin with a cost of £25,000.

There are two exceptions to share pooling that take priority. The same-day rule requires that any tokens bought and sold on the same day are matched first, using the actual cost of the same-day purchase. The 30-day bed-and-breakfasting rule requires that if you sell tokens and buy the same type of token back within 30 days, the sale is matched against the repurchase rather than the pool. These rules exist to prevent people from selling and immediately rebuying the same asset simply to crystallise a gain or loss for tax purposes.

Reporting Crypto Gains

If your total taxable gains from all sources exceed the £3,000 annual exempt amount, you must report them via a Self Assessment tax return. Even if your gains are below £3,000, you must still report if the total proceeds from all disposals exceed four times the exempt amount (£12,000 for 2025/26). This means you may need to file a return even if you made a loss overall.

Crypto gains are reported in the Capital Gains pages (SA108) of the Self Assessment return. You must register for Self Assessment if you have not already done so. The deadline for online filing is 31 January following the end of the tax year — so for gains made in the 2025/26 tax year (6 April 2025 to 5 April 2026), the deadline is 31 January 2027. Late filing attracts an automatic £100 penalty, even if no tax is owed, with further penalties accumulating over time.

You should keep detailed records of every crypto transaction you make, including the date of the transaction, the amount and type of crypto involved, the value in pounds at the time, the purpose of the transaction (purchase, sale, swap, etc.), any fees paid, and the wallet or exchange used. HMRC can request these records at any time, and you are required to keep them for at least five years after the 31 January filing deadline for the relevant tax year.

HMRC has been sending so-called “nudge letters” to individuals it suspects may have unreported crypto gains, based on information received from exchanges. If you receive one of these letters, you should review your tax position carefully and consider making a voluntary disclosure if you have undeclared gains. Failing to report crypto gains can result in penalties of up to 100% of the tax owed, plus interest, and in serious cases of deliberate evasion, criminal prosecution.

DeFi, Staking, and NFTs

The tax treatment of decentralised finance (DeFi) transactions, staking rewards, and non-fungible tokens (NFTs) continues to evolve as HMRC updates its guidance. In general, the same principles apply: if you dispose of a crypto asset at a profit, CGT is due on the gain; if you receive crypto as a reward for an activity, it may be treated as income.

Staking rewards are typically treated as miscellaneous income (or trading income if you stake on a commercial scale). The market value of the tokens at the time you receive them is subject to Income Tax, and that value then becomes the cost basis for any future CGT calculation when you sell or exchange the staked tokens.

Lending crypto through DeFi protocols and receiving interest in return is generally treated as income, taxed at your marginal income tax rate. If you provide liquidity to a DeFi pool and receive liquidity pool tokens in return, HMRC is likely to treat the deposit as a disposal of the original tokens, triggering a CGT event. When you withdraw and receive your original tokens back, that is another disposal of the pool tokens.

NFTs are treated as crypto assets by HMRC. Creating and selling an NFT may be treated as trading income if done on a regular or commercial basis, or as a capital gain on a one-off sale. Buying and later selling an NFT is a straightforward capital gains scenario: your gain is the proceeds minus your cost, including any gas fees or marketplace fees paid.

Example Calculations

The following examples illustrate how crypto Capital Gains Tax is calculated at different gain and income levels, using 2025/26 rates.

£10,000 Gain on £30,000 Salary

A basic rate taxpayer earns a salary of £30,000 and makes £10,000 in crypto gains during the year. The £3,000 annual exempt amount is deducted, leaving a taxable gain of £7,000. With £30,000 of income, there is still plenty of room within the basic rate band (£50,270), so the entire £7,000 taxable gain is charged at 10%. The CGT bill is £700. The effective rate across the full £10,000 gain is 7.0%.

£25,000 Gain on £45,000 Salary

An individual earns £45,000 and makes £25,000 of crypto gains. After deducting the £3,000 exempt amount, the taxable gain is £22,000. The basic rate band runs up to £50,270 of total income. With a salary of £45,000, the remaining basic rate band is £50,270 minus £45,000, which equals £5,270. So £5,270 of the gain is taxed at 10% (£527) and the remaining £16,730 is taxed at 20% (£3,346). The total CGT is £3,873. The effective rate on the full £25,000 gain is 15.5%.

£50,000 Gain on £60,000 Salary

A higher rate taxpayer earns £60,000 and realises £50,000 of crypto gains. After the £3,000 exempt amount, the taxable gain is £47,000. Because their salary already exceeds the £50,270 basic rate band, the entire taxable gain falls into the higher rate at 20%. The CGT bill is £9,400. The effective rate on the full £50,000 gain is 18.8%.

Planning Tips for Crypto Investors

There are several straightforward strategies that can help reduce or defer your crypto CGT liability within the rules.

First, make full use of the £3,000 annual exempt amount each year. If you have unrealised gains, consider selling enough crypto each tax year to use up the exemption, and then rebuying after 30 days if you wish to continue holding. This gradually increases your cost basis and reduces the gain when you eventually sell.

Second, if you are married or in a civil partnership, you can transfer crypto to your spouse tax-free. If your spouse has unused exempt amount or is in a lower tax band, they can then sell the crypto and potentially pay less CGT (or none at all). This is entirely legal and explicitly provided for in the legislation.

Third, keep meticulous records from day one. The cost of crypto accounting software or a professional tax adviser is almost always worth it compared to the risk of penalties for incorrect or late reporting. Many specialist crypto tax tools can connect directly to exchange APIs and generate the figures you need for your Self Assessment return.

Finally, consider the timing of your disposals. If you are close to the end of the tax year and have already used your exempt amount, it may be worth waiting until after 5 April to sell, so the gain falls into the next tax year and benefits from a fresh £3,000 exemption.