UK crypto tax, computed in your browser.
Your crypto tax return, done on your machine, and never paid for twice.
gains.tax computes UK capital gains, income and loss reports entirely in your browser, naming the HMRC matching rule behind every disposal. Free under 1,000 transactions, every report included. Above that, £39 once, covering every tax year you have ever had and every one still to come.
The big-name apps tell you a number.
gains.tax proves it.
676
Same-day under section 105, thirty-day under section 106A, or the section 104 pool, each disposal names the rule that matched it and the law behind it on the row, and every generated report carries its HMRC manual citation.
720
Any CSV, exchange statements, on-chain wallet scans and live exchange sync all land the same way, the count reconciled on screen, row by row. Any row the app refuses is shown with its reason rather than guessed at, and if you are leaving another tax app, its export imports one to one.
720
A reconciliation confidence score with named deductions, per-wallet balancing and fix wizards, so you know exactly how solid the ground under your report is.
The bill that comes back every April, and the one that does not.
The cloud tools charge per tax year or by subscription, so three tax years of reports is three purchases, and the fourth year is another one. Their current figures are in the table below, taken from their own pricing pages.
The same portfolio, the same three years, every report downloaded, here. Under 1,000 transactions the price stays zero. Over it, £39 once, and next April is still zero.
Koinly and CoinLedger both price per tax year. The subscription ones stop your reports the moment you stop paying. All of it is published openly, the numbers below are theirs, checked on the date shown.
| gains.tax | Koinly | CoinLedger | Recap | |
|---|---|---|---|---|
| Price for 1,000 transactions | Free | Their mid tier, per tax year | $99 per tax year | £119 per year, subscription |
| Three tax years | £0 | Three separate purchases | $297 | £119 to £357 depending on when you file |
| Reports on the free tier | All of them | None | None | No free tier |
Prices are each vendor's own published figures, checked 20 August 2026 from their pricing pages. If any of them changes, tell us and this table changes the same week. Full table and sources on the pricing page.
Reports are free here because your machine does the computing. Charging you yearly for arithmetic your own laptop performs is a business model, not a necessity.
Open the network tab. Nothing moves.
Every other tax app works by taking your transaction history onto their servers. gains.tax cannot leak what it never receives. Import your files, run every report, and watch the network panel stay empty. The only optional exception is exchange sync, which talks to Kraken or Binance through a relay that holds nothing, and the app tells you before it happens.
This panel simulates what the network tab shows. Verify it for real, press F12 inside the app and run your whole return.
29 tax rules. 111 assertions.
Every one tested against HMRC's own worked examples.
Every other tax app asks you to trust its arithmetic. This one publishes the arithmetic. The engine's test suite runs with a recorder attached and writes the record below only when every test passes, and the build aborts if a single one fails. Which means the page cannot exist unless the proofs hold.
From export to filed in three steps.
Bring your history
Bring the export from whichever tax app you use today, scan a wallet address, or sync Kraken and Binance. The import count reconciles on screen against your source file.
Read the working
Same-day, bed and breakfast, section 104 pooling, each disposal shows which rule matched and the law behind it, and reports cite the HMRC manual.
Download everything
Capital gains, income, loss claims and around ten more reports, free under 1,000 transactions, ready for self assessment.
Live now the planner, which shows the legal moves that cut your own bill, your remaining allowance, open 30-day windows and a compliance calendar with your specific deadlines. The free tools run the same maths on a single trade, no import needed.
When you want a human, we check them before you meet them.
Directories on other tax platforms list anyone who pays to appear. Ours lists nobody until their professional body membership is confirmed on the register, their identity checked, their practice and insurance confirmed, and their crypto competence tested in a structured interview. The first firms are going through that now, which is why the directory is small. A bar you can read is worth more than a list you cannot. And whoever you pick, one button and one plain email, and your data goes only where you choose to send it.
- Identity verified on the register
- Credential current, checked at source
- Practice real and insured
- Competence tested in interview
- Conduct record clean
- Re-verified every twelve months
Fair questions.
Is it really free
How can it work without a server
What about exchange sync
Will HMRC accept a return prepared with this
Which country does it cover
Can I trust the numbers
What if I already use one of the big-name apps
Run it now, file in January.
The 2025 to 2026 return is due by 31 January 2027. Doing the maths in August and the paperwork in January is a far better year than doing both at once. No signup, no upload, no card, and under 1,000 transactions it stays free.
Run your last three years, free See the live demo