● Built for accountancy professionals

The crypto tax engine
your clients deserve.

HMRC SA108 and IRS Form 8949 reports from any wallet address. Section 104 pooling, bed-and-breakfasting rules, DeFi-aware cost basis. £10 per generated report — no client caps, no monthly minimum.

Try the Engine → View Pricing

£10

Per generated report

Jurisdictions — UK & US

∞

No client caps ever

Cost basis methods

What’s inside

Built deeper than anything
else available.

Every calculation your clients need. Every rule HMRC and the IRS require. Nothing missing.

☷

HMRC Section 104 Pooling

The exact pooling method HMRC requires for UK crypto disposals. Average cost basis tracked across the entire holding period. Same-day and 30-day bed-and-breakfasting rules applied automatically before pooling.

HMRC Compliant

🇺🇸

IRS FIFO / HIFO / LIFO

Full lot-level tracking for US clients. Precise partial lot consumption. Long-term vs short-term holding period calculated per disposal. Form 8949 and Schedule D output with correct 37% and 15% rates applied.

IRS Compliant

📈

Historical Price at Disposal Date

CoinGecko historical prices fetched at the exact timestamp of every disposal — what HMRC requires for accurate GBP valuation. Full audit trail noting price source per transaction.

Audit Trail

💪

Tax Loss Harvesting Engine

Automatically identifies unrealised losses in remaining holdings that could offset gains before year-end. Shows exact potential tax saving per lot. The feature that brings clients back every quarter.

Unique Feature

🔍

“What if I sell today?” Preview

Real-time calculation of the exact tax liability if a client sold their entire holding at the current market price. Net after-tax shown immediately. A conversation-changing tool for client meetings.

Exclusive

📄

Full Mempool Pagination

Complete transaction history — not just the last 25. No missed DeFi interactions, no omitted airdrops, no gaps that could compromise an audit or expose your firm to liability.

Complete Data

Coverage

Two jurisdictions. Every rule. Correctly.

Each jurisdiction implements the statute exactly — not a best-effort approximation.

🇬🇧

United Kingdom — HMRC

HMRC Compliant · Tax Year April 6 → April 5

Section 104 share pooling — average cost basis
Same-day matching rule applied first
30-day bed-and-breakfasting rule applied second
£3,000 CGT annual exempt amount deducted
18% basic rate / 24% higher rate applied
SA108 Capital Gains Summary output
GBP valuation at exact disposal date
Staking, mining, airdrops classified as income

🇺🇸

United States — IRS

IRS Compliant · Tax Year January 1 → December 31

FIFO, HIFO, LIFO — all three methods available
Lot-level tracking with partial lot consumption
Holding period calculated per disposal to the day
Long-term rate 15% (held over 365 days)
Short-term rate 37% (held under 365 days)
IRS Form 8949 output — each disposal itemised
Schedule D totals — short and long-term separated
USD valuation at exact disposal timestamp

Live Engine

Run a real tax report.

Paste any BTC wallet address. The engine fetches complete transaction history from the blockchain — no CSV upload required.

Paste any BTC wallet address

The engine fetches the complete transaction history from the blockchain — no CSV upload, no manual data entry.

Historical prices fetched automatically

CoinGecko provides the exact GBP/USD price at each disposal date — what HMRC and the IRS both require.

Full report returned in seconds

Net gain, estimated tax, CGT allowance remaining, unrealised position, tax loss harvesting opportunities.

Download PDF working paper

Every number cited. Every assumption disclosed. Accountant signature block included. Ready to attach to a client file.

TAXCHAIN ENGINE — LIVE DEMO v2.4.1

$ // Enter a wallet address and click RUN $ // TaxChain Crypto — HMRC & IRS compliant engine

Pricing

Pay per report.
Never per client.

No monthly minimums. No client caps. No upgrade panic mid-January. You pay when you generate a report. That’s it.

Basic

^£10

per report · pay as you go

Full core engine
UK HMRC SA108 output
US IRS Form 8949 output
Section 104 / FIFO lot tracking
Historical prices + audit trail
Mempool pagination (up to 500 txs)
Email support

Get Started →

One endpoint. Complete report.

REST API. Any language. A wallet address goes in, a complete tax report comes out. No SDK required.

A single GET request returns everything your accountant needs — disposals, gains, tax estimates, harvesting opportunities, and unrealised position. The PDF endpoint adds a downloadable working paper ready to attach to a client file.

No authentication required for the preview endpoint. Full report and PDF endpoints require a valid API key delivered on purchase.

// Generate a complete UK tax report

GET /v1/tax/report/{address}
  ?jurisdiction=uk
  &tax_year=2025
  &method=section104

// Response
{
  "jurisdiction": "UK",
  "net_gain_gbp": 24847.50,
  "estimated_tax_gbp": 5243.40,
  "allowance_remaining": 0,
  "disposals_count": 23,
  "harvest_saving": 1847.20,
  "disposals": [ /* full list */ ]
}

// PDF working paper
GET /v1/tax/pdf/{address}?jurisdiction=uk

// "What if I sell today?" preview
GET /v1/tax/preview/{address}

The crypto tax engineyour clients deserve.

Built deeper than anythingelse available.