Capital Gains Tax on shares and crypto explained

The short answer: gains on shares, funds and crypto outside an ISA or pension are taxed at 18% within your unused basic-rate band and 24% above it, after a £3,000 tax-free allowance. Crypto-to-crypto swaps and spending crypto count as sales. Gains are reported through Self Assessment, with tax due by 31 January after the tax year ends.

Tax on different gains

Working out your cost: the pool

If you bought the same share or token several times, you don't pick which ones you sold. They go into one pool (a "section 104 holding") at an average cost:

Selling 150 units at £20 each brings in £3,000. The allowable cost is 150/400 of the pool, £1,875, so the gain is £1,125. Dealing fees on both sides reduce the gain.

Two rules come first: units bought on the same day as a sale are matched first, then units bought in the next 30 days. Only then does the pool apply.

Crypto rules

• Taxable disposals: selling for pounds, swapping for another token (including stablecoins), spending it, and giving it away (except to a spouse or charity).
• Each token has its own pool, across all your wallets and exchanges.
• Fees paid in crypto can count as allowable costs.
• Income, not gains: staking, mining and airdrops received for doing something are usually income when received.
• Lost or stolen crypto is not automatically a loss; you may be able to claim if it has become worthless.
• Reporting: exchanges now collect users' details under new international rules and share transaction data with HMRC, so records should match.

Keep a record of every transaction: date, amount, value in pounds and fees. Crypto tax software can build the pools from exchange exports.

A crypto example

You buy 1 ETH for £2,000, later swap it for Bitcoin worth £3,500, then sell that Bitcoin for £4,200:

The swap is taxable even though no pounds changed hands, and the BTC's cost is its value when you got it. Here the total is under the £3,000 allowance, so no tax is due, but each disposal still counts towards the £50,000 reporting limit.

Using losses

• Same-year losses are taken off gains automatically, before the £3,000 allowance. That can waste some of the allowance, so timing matters.
• Carried-forward losses are only used to bring gains down to the allowance, so none is wasted.
• Report losses within four years of the end of the tax year, even if you have no gains that year.
• Worthless shares or tokens: you can make a negligible value claim to treat them as sold for nothing and create a loss.

Gifts and transfers

Giving shares or crypto to anyone other than a spouse, civil partner or charity counts as selling them at market value, so you may owe CGT on a gift. Transfers to a spouse or civil partner you live with are tax-free, and they take over your original cost. Moving tokens between your own wallets is not a disposal, but keep records so the trail is clear.

Reporting and paying

• Report on your Self Assessment return if your gains are over £3,000, or proceeds over £50,000.
• If you don't usually file a return, register by 5 October after the tax year, or use HMRC's real-time CGT service.
• Pay by 31 January after the end of the tax year.
• Report losses within four years so you can use them later.

Dividends are separate

Dividends from shares are taxed as income, not gains. See dividend tax on shares.

Cutting the tax

Bed and ISA, using a spouse's allowance, selling over two tax years and claiming losses can all reduce the bill. See how to reduce Capital Gains Tax.

Rates for 2026/27, for UK residents. This is general information, not tax advice.