Your crypto taxes,
done right.
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
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.
No same-day or 30-day acquisition matched, so the sale draws from your S104 pool at average cost.
Try it free — no signup required
Paste any Ethereum transaction hash and see it sorted instantly. See exactly how ChainTax identifies swaps, LP positions, staking, and more.
Classify a transaction freeRoute-by-route audit completed April 2026 — auth, payments, concurrency.
Tax engine, classifiers, pricing, API routes.
Same-day, 30-day B&B, S104 pooling. Split-year CGT auto-computed for 2024/25.
Pay per tax year. 14-day refund before download. Secure payment via Stripe.
Gold-level Innovator awarded by InnovateNI, April 2026.
What would HMRC
say you owe?
Paste a wallet address and get an estimated gain and Capital Gains Tax figure in about 30 seconds. Read-only — we never ask for keys or permissions.
- Scans your 50 most recent transactions across 5 chains
- Spots disposals and estimates the gain at HMRC rates
- No signup — your first full scan is free when you are ready
Free · No sign-up
Not sure where you stand?
Paste a wallet, get an estimated tax bill in 30 seconds — no signup needed.
Or classify a single transaction — paste any hash, no wallet needed.
Two paths to your HMRC-ready report
How it works
Exchange trades or DeFi activity — same engine, same accuracy
Export your CSV
Download your transaction history from Coinbase, Binance, or Kraken. Takes 30 seconds.
Import and sort
Upload your CSV — we auto-detect the format and sort every trade, reward, and conversion.
Connect your wallet
Paste your Ethereum, Arbitrum, Optimism, Base, or Polygon address. Read-only — no seed phrase, no permissions.
Automatic sorting
33 protocol-specific detectors identify every interaction — swaps, LPs, staking, bridging, and more.
HMRC matching applied automatically
Same-day rule, 30-day Bed & Breakfast rule, Section 104 pooling — all applied in the correct order. Every disposal shows its working.
Download your report
PDF tax report with SA108 box values pre-filled. Hand it to your accountant or file it yourself.
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. Want to see it on your own figures? You can calculate your crypto tax and watch every disposal get the correct HMRC treatment.
Exchange buy / sell
Most tools
ChainTax
LP position (add / remove)
Most tools
ChainTax
Staking rewards
Most tools
ChainTax
Bridge transfer
Most tools
ChainTax
HMRC matching rules
Most tools
ChainTax
Show Working
Most tools
ChainTax
Exchanges + DeFi combined
Most tools
ChainTax
Split-year CGT (2024/25)
Most tools
ChainTax
Manual entry, shared report links, NFT trades, airdrops and more — see the full comparison →
HMRC already has your exchange data
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 2025/26 return won't match what they already have. Get it right before you file by 31 January 2027.
See the 60-day action planWant background reading first? Read the full guide to the nudge-letter campaign →
UK crypto platforms now reporting your transactions to HMRC under CARF
First automatic data exchange — covering everything you did in calendar year 2026
Nudge letters already going out for 2024/25 onward, based on earlier exchange data
One price. One tax year. No surprises.
Pay once, download your report. No subscriptions, no per-transaction fees.
Free
200 transactions
See your full report — pay only to unlock final amounts
Light
2,500 transactions
Exchange trades, staking, a few swaps
Active
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.
What ChainTax doesn't do yet
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 — so ChainTax now detects them automatically from your stETH balance growth and books each as income at its market value on the date received. It covers every stETH wallet on your account — add another and your next sync recalculates your rebase rewards across the complete set.
- •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; HMRC confirmed in November 2025 that it is developing no-gain-no-loss rules matching the treatment ChainTax applies today, but they are not yet law — 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.
Full detail: How it works → Known limitations
Common questions
The things people ask before they sign up.
Is it safe to connect my wallet?
How accurate is the automatic classification?
What if a transaction is misclassified?
Can my accountant verify the calculations?
Which exchanges and chains do you support?
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?
Why is ChainTax cheaper than other crypto tax tools?
I had over 10,000 transactions last year. Now what?
Still have questions? hello@chaintax.co.uk — we read every email.
Popular guides
Stop paying tax you do not owe
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.
See your disposals — free200 transactions free · 14-day refund before download · Stripe secure