Built for UK crypto tax professionals

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 — you review the audit trail and sign off.

Built by a UK crypto investor who needed this for his own accountant.

The DeFi client problem

Replace 3 hours of tracing with a 5-minute review

Your client connects their wallets and imports exchange CSVs. ChainTax classifies every transaction across 27 protocols and 5 chains, then shares a read-only report link with you. You verify and file.

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 — classified automatically
  • S104 pools built per asset from first acquisition
  • Same-day and B&B matching on every disposal
  • Full audit trail per disposal — Show Working
  • Shared report link — no login required

Review in minutes. Bill for advice, not data entry.

1Client signs up2Connects wallets or imports CSVs3ChainTax classifies4Client shares report link5You review and sign off

The feature accountants actually need

Show Working — every line, fully auditable

Every disposal shows the matching rule applied, the S104 pool snapshot before and after, the gain calculation, and the SA108 box it maps to. No black boxes. No "trust us".

  • 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 classifications flagged for your review
  • Shared via read-only link — no login required
Capital GainUniswap V3 Swap
High confidence
Disposed
2.4500 ETH
Acquired
7,841.23 USDC
Date
14 Mar 2025, 09:42 GMT
Matching Rule — Section 104 Pool
Pool before
14.8200 ETH @ £1,247.33 avg
Disposed from pool
2.4500 ETH
Allowable cost
£3,055.96
Pool after
12.3700 ETH @ £1,247.33 avg
Gain Calculation
Proceeds
£6,273.18
Allowable cost (S104)
£3,055.96
Gas fee
£4.12
Chargeable gain
£3,213.10
SA108/Box 13.2 (proceeds)/Box 13.4 (gains)

The maths

See what ChainTax saves your practice

Adjust the numbers to match your practice. ChainTax Unlimited is a one-time £179 per client per tax year — no subscriptions.

10
1100
3
1 hr8 hrs
£200
£50£500
Manual cost per client£600
ChainTax Unlimited£179
Saving per client+£421
Annual saving (10 clients)+£4,210

in time costs recovered — before accounting for new clients you can now accept profitably.

See it on a real DeFi portfolio

We'll set up a demo with your most complex client type — every transaction classified, every disposal with Show Working, full SA108 output.

Or email us directly at hello@chaintax.co.uk