DeFi clients don't have to be your worst margin.
1,000+ on-chain transactions per client. S104 pools built by hand. Same-day and B&B rules applied manually. ChainTax does all of it, so you review the audit trail and sign off.
Built by a UK crypto investor who needed this for his own accountant. Read the story →
Are you a crypto investor wondering if you need an accountant? See our pricing.
The DeFi client problem
Turn raw history into a focused review
Your client connects their wallets and imports exchange CSVs. ChainTax applies supported rules across 34 protocol classifiers and 5 chains, flags unresolved activity, then shares a read-only report link with you. You decide what needs further evidence before filing. With the first CARF reports covering 2026 activity due by 31 May 2027, a clear reconciliation trail matters more than ever.
Without ChainTax
- Trace each swap, stake, and LP on Etherscan
- Build S104 pools in spreadsheets
- Apply same-day and 30-day B&B rules by hand
- Cross-reference token prices at disposal time
- Fill SA108 boxes 13.1–13.8 manually
Result: you eat the margin or turn the client away.
With ChainTax
- Client connects wallets, sorted automatically
- S104 pools built per asset from first acquisition
- Same-day and B&B matching on every disposal
- Full audit trail per disposal, via Show Working
- Read-only share link to the full report, with no CSV ping-pong
Review in minutes. Bill for advice, not data entry.
The feature accountants actually need
Show Working: every line, fully auditable
Every disposal shows the matching rule applied, the S104 pool snapshot, the gain calculation, the price source, and confidence. The report separately maps aggregate totals to the SA108 boxes. No black boxes. No "trust us". See an illustrative calculation trail behind the reports before you request a demo.
- Same-day, B&B, or S104 matching rule tagged per disposal
- Pool size and average cost shown before and after
- SA108 boxes 13.1–13.8 + Box 51 split-year auto-computed
- Low-confidence results flagged for your review
- Shared via read-only link, a fixed snapshot, so the figures can't shift mid-review
The maths
Model the workflow with your own figures
Each client runs ChainTax on their own wallets and exchanges. You review the Show Working output and decide what is ready to file. Review time varies with data quality and portfolio complexity, so the calculator below uses editable assumptions rather than a claimed typical saving. One Active tax-year purchase (£99, up to 10,000 transactions) covers one client's selected tax year, with no subscription and no per-seat billing. For higher-volume clients, the Concierge sync is quoted on a per-portfolio basis.
in time costs recovered, before accounting for new clients you can now accept profitably.
Illustrative model only. It compares your entered staff time at your entered hourly rate, then includes the £99 ChainTax Active cost per client. It is not a promise of time or cash savings.
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.
- •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, so 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
See it on a real DeFi portfolio
I'll set up a demo with your most complex client type: every transaction sorted, every disposal with Show Working, full SA108 output.