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AI Summary

  • Follows HMRC rules including Section 104 pooling for cost basis and the 30-day bed-and-breakfasting rule
  • Capital Gains Tax allowance is £3,000 for 2024-25; gains above this are taxed at 10% (basic rate) or 20% (higher rate)
  • Includes income events such as staking and airdrops where applicable
  • Report is structured for use with Form SA108 (Capital Gains Summary) in Self Assessment
  • Share with your accountant or use directly for Self Assessment filing
UK crypto taxes follow HMRC rules, which means Section 104 pooling, the 30-day bed-and-breakfasting rule, and Capital Gains Tax allowances. The KoinX Complete Tax Report for UK users applies these rules automatically, giving you a report ready for your Self Assessment tax return.

What Is in This Report?

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SectionWhat It Shows
HMRC Capital Gains SummaryTotal crypto disposals and capital gains
Summary of Income from Crypto DerivativesProfit and loss from futures and options trading
Other Income and Expense SummaryAirdrops, rewards, staking, mining income
Beginning of Year BalanceAsset holdings at start of tax year
End of Year BalanceAsset holdings at end of tax year
Capital Gains TransactionsDetailed list of all disposals
Crypto Derivatives TransactionsDetailed futures and options trades
Other Income & Expense TransactionsIncome and expense events
Asset Wise Profit & LossProfit and loss breakdown by asset
Data SourcesExchanges, wallets, or files used to generate report
This report compiles all your crypto tax information into one document for Self Assessment filing or sharing with your accountant.

How HMRC Treats Crypto

HMRC treats cryptocurrency as property (similar to stocks). Capital Gains Tax applies when you sell, trade, or spend crypto. Income Tax applies when you receive crypto as income (staking, airdrops, mining). The CGT Allowance is the first £3,000 of gains tax-free (2024-25 onwards; was £6,000 in 2023-24). CGT rates are 10% for basic rate taxpayers and 20% for higher rate taxpayers on gains above the allowance.

HMRC Capital Gains Summary

This section summarises all crypto disposals during the tax year.
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FieldDescription
Number of DisposalsTotal number of crypto disposals
Disposal ProceedsTotal value received from disposals
Allowable CostsTotal purchase cost of disposed assets
Gains Before LossesGross profit from disposals
Losses in the YearTotal losses recorded
Net Capital GainsFinal gains after subtracting losses
The report also includes Self Assessment filing tips, explaining how to report these numbers in Form SA108 (Capital Gains Summary).

Summary of Income from Crypto Derivatives

If you trade crypto derivatives such as futures or options, this section summarises your trading performance.
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FieldDescription
Total Realised ProfitTotal profit from derivatives trading
Total Realised LossesTotal losses from derivatives trading
Total Margin FeesTrading fees paid or received
Net Profit and LossFinal profit after accounting for losses and fees
This section provides a high-level overview of derivatives trading activity during the tax year.

Other Income and Expense Summary

This section records crypto received as income, rather than through trading.
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Examples include:
  • Airdrops
  • Staking rewards
  • Mining income
  • Salary received in crypto
  • Consultancy payments
Income values are calculated based on the market value of the asset at the time it was received. The section also include expenses, such as:
  • Margin interest
  • Mining expenses
  • Donations
  • Consultancy expenses
  • Brokerage fees

Section 104 Pooling Explained

Unlike FIFO, the UK uses pooled cost basis. All holdings of the same crypto asset are combined into a pool. The pool tracks total quantity and total cost. When you sell, the cost basis is the average cost per unit from the pool. Example: Buy 1 BTC at £20,000, then buy 1 BTC at £30,000. Pool: 2 BTC with £50,000 cost. Average price = £25,000 per BTC. Sell 1 BTC at £35,000. Gain = £10,000. KoinX automatically applies Section 104 pooling for UK users.

The 30-Day Rule (Bed and Breakfasting)

HMRC prevents loss harvesting through the 30-day rule. If you sell crypto and repurchase the same asset within 30 days, the sale must be matched with the repurchase transaction instead of the pool. Example: Sell 1 BTC at £35,000, then rebuy 1 BTC at £33,000 within 30 days. Gain = £2,000. KoinX applies this rule automatically when generating the report.

Same-Day Rule

HMRC matching rules follow this order: same-day matching first, then the 30-day rule, then the Section 104 pool. KoinX applies this order automatically during tax calculations.

Detailed Beginning of Year Balance of Assets

Shows the portfolio position at the start of the financial year.
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Detailed End of Year Balance of Assets

Shows the portfolio position on the last day of the financial year.
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Why these reports matters:
  • Shows your starting position for the year
  • Helps verify that cost basis carry-forward is correct
  • Useful for audit trail and reconciliation

Capital Gains Transactions

This section lists every taxable disposal of cryptocurrency.
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FieldDescription
Date PurchasedWhen the asset was acquired
Date SoldDisposal date
AssetCryptocurrency traded
QuantityAmount sold
Buy ValuePurchase price
Sell ValueSale price
Gains or LossesProfit or loss from the transaction
ExchangeSource of transaction data
This provides a detailed audit trail for HMRC reporting.

Crypto Derivatives Transactions

If derivatives trading occurred, the report includes a detailed list of these trades.
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FieldDescription
DateTrade date
AssetUnderlying asset
QuantityContract size
Net GainProfit or loss
TypeFutures or Options
These transactions support the derivatives summary earlier in the report.

Other Income & Expense Transactions

This section lists every income and expense event recorded during the tax year.
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Examples include:
  • Staking rewards
  • Airdrops
  • Mining income
  • Salary payments
  • Donations
  • Funding fees
  • Consultancy income
These records provide detailed documentation for income reporting and expense tracking.

Asset Wise Profit & Loss

This section summarises profit and loss for each cryptocurrency asset.
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AssetGross ProfitGross LossNet Gains
LUNA£0.19£0£0.19
ETH£213,940.17£58,801.30£155,138.86
ZK£509.66£0£509.66
This helps identify which assets generated the most gains or losses.

CGT Allowance and Rates

For the 2024-25 tax year:
Your GainsTax
Up to £3,000Tax-free
Above £3,000 (basic rate taxpayer)10%
Above £3,000 (higher rate taxpayer)20%
The report shows your total gains so you can determine how much exceeds the CGT allowance.

Data Sources

The final section lists all integrations used to generate the report, including exchanges, wallets, and custom files. This ensures transparency about where the transaction data came from.
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Frequently Asked Questions

The Complete Tax Report (UK) is your main document. It includes HMRC-compliant calculations and summaries for Self Assessment.
If you sell and repurchase the same asset within 30 days, the sale is matched to the repurchase price rather than the Section 104 pool. KoinX automatically applies this rule.
Yes. The report uses Section 104 pooling, applies same-day matching, the 30-day rule, and calculates capital gains according to HMRC guidance.
Yes. Losses can offset gains in the same year or be carried forward to future tax years.
10% for basic rate taxpayers and 20% for higher rate taxpayers, after the £3,000 CGT allowance.
Last modified on March 13, 2026