TaxChain Crypto — Institutional Crypto Tax Engine

What's Inside

Built deeper than
anything else available.

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

01 — CORE ENGINE

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 SA108 Ready Section 104

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. Short-term 37%, long-term 15% rates applied correctly.

IRS Compliant Form 8949 Schedule D

02 — PRICE DATA

Historical Price at Disposal Date

CoinGecko historical prices fetched at the exact timestamp of every disposal — what HMRC requires for accurate GBP valuation. 24-hour caching prevents rate limiting. Full audit trail noting price source per transaction.

Audit Trail CoinGecko GBP Valuation

03 — TAX INTELLIGENCE

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 makes clients come back every quarter, not just in January.

Unique Feature Loss Harvesting Year-End Planning

04 — SELL PREVIEW

"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 — no competitor offers this as an API endpoint.

Exclusive Real-Time Client Meetings

05 — TAX YEAR LOGIC

Automatic Jurisdiction Routing

UK tax year runs April 6th to April 5th. US runs January 1st to December 31st. The engine detects the current tax year per jurisdiction automatically. One API call, correct rules applied, correct period filtered.

Auto-Detection Multi-Year Period Filtering

06 — UNREALISED P&L

Unrealised Gains & Losses

Full mark-to-market on remaining holdings at current price. Unrealised gains and losses broken out separately. Remaining BTC holdings tracked to satoshi precision. Everything an accountant needs for a complete client picture.

Mark-to-Market Portfolio View Satoshi Precision

Coverage

Two jurisdictions.
Every rule. Correctly.

🇬🇧

United Kingdom

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 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 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. Everything.

Retrieve the same report free. You only pay £10 when you generate. Re-downloading a stored report is always free. Fair.

TAXCHAIN ENGINE — LIVE DEMO

v2.4.1

// TaxChain Crypto — Institutional Tax Engine

// Enter a BTC wallet address below to run a live report

$ Awaiting wallet address...

Pricing

Pay per report.
Never per client.

No monthly minimums. No client caps. No upgrade panic mid-January. You pay £10 when you generate a report. That's it.

Starter

^£99

includes 15 reports · £10 each after

15 report credits included
UK HMRC SA108 output
US IRS Form 8949 output
Tax loss harvesting analysis
Sell-today preview endpoint
Stored reports — free re-download
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.

// Generate a complete UK tax report — one API call

const response = await fetch('https://api.taxchaincrypto.com/v1/taxchain/report/{address}', {
  method: 'GET',
  headers: { 'X-API-Key': 'tc_live_...' },
  params: { jurisdiction: 'uk', tax_year: 2025, method: 'section104' }
});

// Response includes everything your accountant needs

{
  "jurisdiction": "UK",
  "tax_year": 2025,
  "period": "2025-04-06 → 2026-04-05",
  "net_gain_usd": 24847.50,
  "estimated_tax_usd": 5243.40,
  "allowance_remaining_usd": 0,
  "disposals_count": 23,
  "unrealised_gains_usd": 8420.00,
  "harvest": {
    "potential_tax_saving_usd": 1847.20,
    "opportunities_count": 3
  },
  "disposals": [ /* full disposal list */ ]
}

// Preview endpoint — "what if I sell today?"

GET /v1/taxchain/preview/{address}?jurisdiction=uk

The tax engineyour clients deserve.

Built deeper thananything else available.

Two jurisdictions.Every rule. Correctly.

Run a realtax report.

Pay per report.Never per client.

One endpoint.Complete report.

The tax engine
your clients deserve.

Built deeper than
anything else available.

Two jurisdictions.
Every rule. Correctly.

Run a real
tax report.

Pay per report.
Never per client.

One endpoint.
Complete report.