Do You Pay Tax When You Sell Crypto in the UK?

Tax year 2025/26 (6 April 2025 to 5 April 2026). Last updated October 2026.

Short answer: selling crypto is a disposal for Capital Gains Tax. You pay tax only on the gain (what you got minus what it cost you), and only on total gains for the year above the £3,000 annual exempt amount. Whether you have to report is a separate question, covered below.

Which actions count as a disposal

HMRC treats each of these as disposing of a cryptoasset:

• Selling it for pounds or any other currency.
• Swapping it for another token, including stablecoins. ETH to USDC is a disposal of ETH, even though no pounds changed hands.
• Spending it on goods or services.
• Giving it away, except to your spouse or civil partner. A gift is valued at the market price on the day.
• Paying a network fee in crypto. The tokens spent on the fee are a tiny disposal of their own.

These are not disposals:

• Buying crypto with pounds.
• Holding it, however much the price moves.
• Moving it between wallets or exchanges you own.
• Giving it to your spouse or civil partner.

How to work out the gain

For each disposal:

Gain = disposal value in GBP − allowable cost

The allowable cost is not simply what you paid for "those" coins. UK rules match a disposal against your purchases of the same token, in this order:

1. Same day. Tokens you bought on the same day as the sale.
2. Next 30 days. Tokens you buy in the 30 days after the sale (the "bed and breakfast" rule, which stops you selling and rebuying to bank a loss).
3. Section 104 pool. Everything else, at the average cost of every unit you still hold.

You can also deduct transaction fees paid to buy and sell, and certain costs of making the transaction. You cannot deduct the cost of the computer or the electricity used to trade.

Worked example

• 2023: buy 1 ETH for £2,000.
• 2024: buy 1 ETH for £3,000. Your pool is now 2 ETH costing £5,000, so £2,500 per ETH.
• August 2025: sell 1 ETH for £4,000. Nothing was bought that day or in the next 30 days, so it comes from the pool at £2,500.
• Gain: £4,000 − £2,500 = £1,500. That is under the £3,000 allowance on its own, so no tax is due if it is your only gain.

Repeat that for every sale, swap and spend across every token and exchange, and you have the year's figure. That repetition is where most people get stuck.

The allowance and the rates

The allowance covers all your capital gains together, not crypto alone. Which rate applies depends on how much of your basic-rate band your income has already used.

Losses

A disposal for less than its allowable cost is a loss. Losses reduce gains in the same year first. Unused losses carry forward, but only if you report them to HMRC within four years of the end of the tax year you made them in. More in our guide to crypto losses.

When you have to tell HMRC

You need to report crypto disposals if, for the tax year:

• your total gains are above the £3,000 allowance, or
• the total you received from disposals was more than £50,000, even if no tax is due, as long as you are registered for Self Assessment.

If you file a Self Assessment return, the figures go on the SA108 Capital Gains Summary. See SA108 for crypto for the boxes. If you do not file a return, HMRC's real-time Capital Gains Tax service lets you report and pay a gain by 31 December after the tax year.

Key 2025/26 dates:

• 5 October 2026: register for Self Assessment if this is your first year with a gain to report.
• 31 January 2027: online return and payment deadline.

Crypto that is income, not a gain

Some crypto is taxed as income when you receive it: staking rewards, mining, most airdrops, and crypto paid as wages. You pay Income Tax on its GBP value on the day it arrives. When you later sell it, that value becomes its cost for Capital Gains Tax.

Records HMRC expects you to keep

For every transaction: the token, the date, whether you bought or disposed of it, the number of units, its value in pounds at the time, and a running pool cost. Exchange exports often miss transfers, fees or delisted tokens, so check them before you rely on the totals.

Got a letter from HMRC?

HMRC writes to people it knows hold crypto, using data from UK exchanges. A letter sets its own deadline. See what to do about an HMRC crypto letter.

Let Moonscape do the matching

Moonscape imports your exchange and wallet history, applies the same-day, 30-day and Section 104 rules for each token, and gives you the SA108 box figures with the computation behind every number. See how it works for UK filers.

This guide explains HMRC's general rules. It is not personal tax advice. If your situation is unusual (non-UK residence, trading as a business, very large DeFi activity), talk to a tax adviser.