Import from Coinbase, Binance, or Kraken in 30 seconds. Connect DeFi wallets for automatic sorting. HMRC-ready reports with full working shown — Section 104 pooling, same-day matching, SA108 box mapping.
200 transactions free · From £49 per tax year · No subscriptions ever
Show Working
Every disposal, fully shown.
Most tax tools hand you a PDF and a total. ChainTax shows the matching rule applied, the S104 pool before and after the sale, the price source, and a confidence rating — for every disposal in your report.
HMRC matching rule applied (Same-day, B&B, or Section 104)
Pool cost basis before and after the disposal
Price source (Kraken, DefiLlama, CoinGecko, or your manual entry)
Confidence rating — High, Medium, or Low
Your accountant can verify every line — or share a live link directly to their dashboard.
chaintax.co.uk/transactions
DisposalHHigh confidence3 Jul 2024
Sold
1.5000 ETH
Gain
+£1,847.50
Matching rule
Average cost (HMRC Section 104)
No same-day or 30-day acquisition matched, so the sale draws from your S104 pool at average cost.
S104 pool
Units
Cost basis
Before
8.2400 ETH
£18,492.00
This disposal
−1.5000 ETH
−£3,366.07
After
6.7400 ETH
£15,125.93
Proceeds £5,213.57·Cost £3,366.07
Price: Kraken close
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Paste any Ethereum transaction hash and see it sorted instantly. See exactly how ChainTax identifies swaps, LP positions, staking, and more.
Works for everyone. Gets the hard stuff right too.
Most tools handle simple trades. When it gets complex, they get it wrong. ChainTax sorts DeFi protocols most tools miss — with a Needs-review queue for anything unrecognised. You stay in control.
Under CARF, ~50 UK crypto platforms now report your transactions directly to HMRC. The first automatic exchange lands May 2027, covering calendar year 2026. HMRC is already sending nudge letters for 2024/25 based on earlier exchange data.
If your crypto activity is misread — tax you do not owe, missing cost basis, income counted twice — your return won't match what they already have. Get it right before you file.
Pay once, download your report. No subscriptions, no per-transaction fees.
Free
£0forever
200 transactions
See your full report — pay only to unlock final amounts
Light
£49/tax year
2,500 transactions
Exchange trades, staking, a few swaps
Most popular
Active
£99/tax year
10,000 transactions
Active across exchanges and DeFi
A UK crypto-specialist accountant typically charges £300+ to sort 50 transactions manually. Above 10,000 transactions? Concierge sync — quote-first, run by us.
No tax tool is perfect. Here's what ChainTax cannot yet handle automatically — and what you should check manually or discuss with your accountant.
•Aave interest (aTokens) accrues via balance changes rather than individual transactions, so it doesn't appear in your transaction history. For now, add aToken interest manually as an income event — automatic detection via daily balance snapshots is on the roadmap.
•Lido stETH rebase rewards happen at the protocol level and rarely appear as transactions in your wallet. Add them manually as income for now — automatic detection via daily balance snapshots is on the roadmap.
•Deposits into Aave, Compound, Yearn, EigenLayer, and similar fixed-ratio lending or staking protocols are treated as transfers, not disposals — your cost basis carries to the receipt token (aToken, cToken, vault share). HMRC's strict reading (Cryptoassets Manual CRYPTO61620) could treat these as deemed disposals at deposit; pending NGNL legislation is expected to confirm the no-gain-no-loss treatment ChainTax applies today, but if you want strict-reading compliance, override the deposit event manually.
•Some protocols return ETH via internal calls (Nexus Mutual, Rocket Pool, cbETH). We catch most of these automatically; when we can't, we flag the event for your review.
•Five EVM chains supported: Ethereum, Arbitrum, Optimism, Base, and Polygon. Other chains (Solana, Avalanche, etc.) are not yet covered.
Yes. ChainTax only ever sees your public wallet address — read-only on-chain data. We never ask for a seed phrase, private key, or any signing permission. The same data anyone with your address can see on Etherscan is what we use to build your report.
How accurate is the automatic classification?
Every disposal is matched against HMRC rules — Same-day → 30-day Bed & Breakfast → Section 104 pooling — in the correct order. 33 protocol-specific detectors handle Uniswap, Aave, Lido, Curve, GMX and more — protocols that generic tools misclassify as phantom gains. Anything we cannot recognise lands in a Needs-review queue rather than getting a wrong answer silently.
What if a transaction is misclassified?
Edit it. Every transaction has an Edit button — change the type, set the proceeds, set the cost basis, override the asset. Your edit is preserved on every future re-sync, so you only need to fix something once. The report regenerates automatically.
Can my accountant verify the calculations?
Yes. Generate a shareable read-only link from your report — your accountant sees every disposal, every matching rule, the cost basis before and after each sale, and the price source. No login needed on their side. The PDF report also pre-fills SA108 box values (13.1–13.8 plus Box 51 split-year adjustment for 2024/25).
Which exchanges and chains do you support?
CSV import: Coinbase, Binance, Kraken (auto-detected), plus Koinly export for any exchange Koinly already supports. On-chain: Ethereum, Arbitrum, Optimism, Base, and Polygon. Solana, Avalanche, BSC and others are not yet covered — for those, manual entry or a Koinly CSV is the workaround for now.
What about NFTs, staking rewards, or trades I made before signing up?
NFT marketplace trades on OpenSea, Blur, and Treasure Trove are auto-classified with FIFO cost basis tracking. For NFTs from other marketplaces, add the cost basis manually — once. Staking rewards on supported protocols (Lido, Rocket Pool, Curve, Atlas Mine, Synthetix) are picked up automatically. For pre-sync activity that we cannot reconstruct from on-chain history, the manual-entry flow lets you add buys, sells, and income at the right historical price.
Why is ChainTax cheaper than other crypto tax tools?
No subscription. You pay per tax year — £49 (Light, up to 2,500 transactions) or £99 (Active, up to 10,000 transactions). One payment, one report. Most tools renew you annually whether you trade that year or not. A UK crypto-specialist accountant typically charges £300+ to hand-sort even 50 transactions, so £49 for the engine to do thousands automatically is the deliberate floor.
I had over 10,000 transactions last year. Now what?
Concierge sync. We run the import on a service account, walk through any Needs-review items with you, and hand you the same report you would have gotten self-serve. Quote-first, typically £249–£449 depending on portfolio shape. Email hello@chaintax.co.uk with your wallet address and we will reply with a quote.
Import your exchange trades or connect your DeFi wallets. See every disposal sorted, every matching rule applied, and the working shown line by line. Pay only when you download the report.