How to calculate crypto capital gains tax in the UK
Quick answer: To calculate crypto capital gains tax in the UK, import or add your trades, check the matching, read your tax year totals and copy the SA108 figures.
- Import or add your trades. Upload a CSV from Coinbase, Binance or Kraken, or a simple file with date, type, asset, amount, total and fee. Values must be in pounds.
- Check the matching. Each disposal shows which rule matched it: same-day, 30-day (bed and breakfast) or the Section 104 pool, and the allowable cost.
- Read your tax year totals. Proceeds, allowable costs, gains and losses per tax year, after the annual exempt amount.
- Copy the SA108 figures. Number of disposals, proceeds, allowable costs, gains and losses go in the cryptoasset section of the capital gains pages.
HMRC's matching rules
HMRC doesn't use FIFO for tokens. A disposal is first matched with tokens of the same type bought the same day, then with tokens bought in the next 30 days, and only then with the Section 104 pool, which holds all your other tokens of that type at their average cost. Each token type has its own pool.
Tax years, allowance and rates
The UK tax year runs from 6 April to 5 April. The annual exempt amount is £3,000 from 2024-25 (£6,000 in 2023-24, £12,300 before). Gains above it are taxed at 18% within your basic rate band and 24% above it for disposals from 30 October 2024; before that the rates were 10% and 20%.
What counts as a disposal
Selling tokens for pounds, swapping one token for another, spending tokens on goods and giving them away (except to a spouse or charity) are all disposals. Moving tokens between your own wallets is not. This calculator covers buys, sells and swaps; staking, airdrops and forks need separate treatment.
Frequently asked questions
Why doesn't HMRC use FIFO?
Capital gains on tokens follow the share-matching rules for pooled assets: same-day, then 30-day, then the Section 104 pool at average cost (HMRC Cryptoassets Manual CRYPTO22200).
Do I have to report my crypto?
You fill in the capital gains pages if your total disposal proceeds were over £50,000, your gains before losses were over the annual exempt amount, or you want to claim a loss.
Can I deduct fees?
Yes. Fees for buying are part of the cost, and fees for selling are a cost of the disposal. For a token-to-token swap, HMRC accepts splitting the fee 50/50 between the two sides.
What do I get with the paid report?
The on-screen totals are free. The PDF report lists every disposal, the rule used for each match, the allowable costs and a summary per tax year with your SA108 figures, ready to keep with your records.
Is this tax advice?
No. It calculates from the trades you enter, using HMRC's published rules. Check the result, and ask a tax adviser if your situation is complex.