CryptoTax UK works out your capital gains with HMRC's exact share matching rules — same-day, 30-day bed & breakfast, Section 104 pooling — entirely on your phone. Import your exchange history, resolve what the engine flags, export an SA108-ready report.
Get early accessFree during early access · Tested against HMRC's worked examples · Built in Liverpool by Hale Technology
Since 1 January 2026, crypto exchanges collect and report UK users' transactions to HMRC automatically under the Cryptoasset Reporting Framework — including platforms based overseas. The first reports land on HMRC's desk in 2027, covering this year's activity.
Failing to give your exchange accurate details risks a penalty of up to £300 before any tax is even assessed. Under-reported gains cost far more. The question isn't whether HMRC sees your trades — it's whether your figures match theirs.
Most tax tools quietly invent a cost basis when your history has gaps. Ours refuses — because a made-up number is exactly what an HMRC enquiry finds.
A disposal with no matching purchase gets a £0 cost basis and a loud warning on every screen and report — the figure can't pretend to be complete until you fix the record.
Once saved, a valuation can't be silently edited — corrections are recorded as delete-and-re-add. If HMRC ever asks, your records show their own history.
Withdrawals are paired with deposits by asset, amount and timestamp — and you confirm each pair. Tokens that left and never arrived get flagged as possible disposals, not ignored.
Coinbase, Kraken and Binance exports auto-detected. Duplicates skipped. Every line's fate shown before anything saves.
Confirm your own wallet moves. Resolve anything that looks like an unreported disposal or a missing cost basis.
Every disposal shows its same-day, bed & breakfast and Section 104 breakdown. Warnings stay visible until resolved.
SA108-ready figures plus a disposal-by-disposal appendix your accountant will actually thank you for.
Every rule is pinned by an automated test suite built from hand-computed worked examples — including a stress scenario covering the exact 30-day boundary, contested buy-back claims between competing disposals, and matching across the tax-year end. If a code change ever breaks a figure, the build fails before it reaches you.
| Rule | What it means for you |
|---|---|
| Same-day matching | Sales match purchases made the same day first. |
| 30-day bed & breakfast | Sell and rebuy within 30 days? The sale matches the rebuy — earlier disposals claim it first, per statute. |
| Section 104 pooling | Everything else is matched at your pooled average cost, per asset. |
| Crypto-to-crypto swaps | Every swap is a disposal at market value — including into stablecoins. |
| 30 Oct 2024 rate change | Disposals dated before and after are charged at the right rates — the straddle year is computed correctly. |
| Staking & mining income | Miscellaneous income at value on receipt, with the £1,000 allowance applied — kept separate from your capital gains. |
| Gratuitous airdrops | Tokens you gave nothing for aren't income at all — recorded as CGT-only acquisitions at market value. You classify; the app never guesses. |
The position explorer shows this year's realised gains against the annual exempt amount, and every holding's pooled cost basis against its live market value — with the 30-day rule stated plainly next to any figure it affects, including a warning when a recent purchase means a sale wouldn't come from your pool. It states your position and the tax mechanics; the decisions stay yours.
Every calculation runs on-device. The optional backup is encrypted before it leaves your phone with a passphrase only you hold — our server stores a blob it cannot read. HMRC gets your data from your exchange either way; nobody needs to get it from us.
Yes. From 1 January 2026, exchanges collect and report UK users' transaction data to HMRC automatically under CARF, with first reports arriving in 2027 — and HMRC already receives data from UK platforms under existing powers.
Yes — HMRC treats every crypto-to-crypto swap as a disposal at market value in pounds, including swaps into stablecoins. The app records each swap as a disposal and a linked acquisition automatically.
The engine flags every disposal it can't match and shows you exactly what's missing. It never invents a cost basis to make the numbers look finished — you fix the record, the figures update.
The matching engine is locked down by an automated test suite built from hand-computed worked examples: the same-day rule, both edges of the 30-day window (day 30 in, day 31 out), competing buy-back claims resolved in statutory order, pooling to the penny, and matching across the tax-year boundary. Every disposal in your report also shows its full rule-by-rule breakdown, so nothing asks to be taken on trust.
For complex affairs, possibly — and the export is built for that conversation: an SA108 summary plus a disposal-by-disposal matching appendix. The app produces estimates, not tax advice.
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