One price. One tax year. Done.
Pay once, download your HMRC-ready report.
No subscriptions. No per-transaction fees. No surprises.
Import or scan 200 transactions free — pay only when you download.
Pay once · 14-day refund before download · Secure payment via Stripe
Over 10,000 transactions?
We'll run a Concierge sync for you — quote-first, no commitment.
Questions? hello@chaintax.co.uk — we typically reply within a few hours.
Filing 2025/26 & 2026/27?
Get both tax years in one checkout and save.
Light
£98 separately
Active
£198 separately
Bundle covers 2025/26 and 2026/27. Already purchased one year? Buy each year individually to upgrade.
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
Route-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.
Common questions
Which tax rules does ChainTax apply?
All three HMRC matching rules: same-day, 30-day bed-and-breakfast, and Section 104 pooling (average cost basis). Bridging and ETH→WETH wrapping are correctly treated as non-disposal transfers. CGT runs at 18%/24% for 2025/26 and 2026/27 disposals; 2024/25 was the one split year, taxed at 10%/20% before 30 Oct 2024 and 18%/24% after — applied per disposal.
What do I get for free?
Import exchange CSVs or connect your wallets and classify up to 200 transactions. View your full report summary, every classification with confidence ratings, and Show Working for each disposal. PDF and CSV downloads require a purchase.
Can I upgrade later?
Yes. Buy Light now and upgrade to Active later — you only pay the difference. Your data stays intact.
What if a classification looks wrong before I file?
You can manually edit transactions before downloading your report, including the tax type and notes for anything that needs an override. If you are unsure, email hello@chaintax.co.uk and we will help you check it before you file.
Why per tax year, not a subscription?
You file once per year, so you pay once per year. Each purchase covers one UK tax year (6 April to 5 April). No recurring charges, no auto-renewals.
Which chains and exchanges are supported?
On-chain wallet scanning for Ethereum, Arbitrum, Optimism, Base, and Polygon. CSV import from Coinbase, Binance, and Kraken. Centralised exchange rows from Koinly (including non-EVM exchange trades) are fully supported as manual entries. On-chain activity from non-EVM chains isn't classified automatically.
How does this compare to an accountant?
A UK crypto-specialist accountant typically charges £300+ to manually classify 50 transactions. ChainTax classifies thousands automatically — exchange trades and DeFi — with full working shown, from £49.
What happens if HMRC changes the SA108 format?
We update ChainTax each tax year to match the latest HMRC guidance. When HMRC introduced dedicated crypto boxes (13.1–13.8) on SA108 for 2024/25, we shipped support on day one — including the split-year CGT rate change. Future format changes will be handled the same way.
Further reading
Switching from another tool?