Crypto Tax Calculator UK 2025/26

UK crypto gains are subject to Capital Gains Tax. For 2025/26, you have a £3,000 annual tax-free allowance. After that:

• Basic rate taxpayers (income up to £50,270): 18% on gains
• Higher/additional rate taxpayers: 24% on gains

Example: £10,000 gain - £3,000 allowance = £7,000 taxable. At 18% = £1,260 tax, at 24% = £1,680 tax.

Yes! Trading one cryptocurrency for another (e.g., Bitcoin for Ethereum) is a taxable disposal in the UK. You must calculate the gain as:

• GBP value of crypto RECEIVED at time of trade (proceeds)
• Minus: Your cost basis of crypto SOLD
• Equals: Taxable gain (or loss)

This is one of the most commonly missed taxable events. HMRC receives data from major exchanges and can identify unreported trades.

Staking and mining rewards are taxed TWICE:

1. Income Tax when received: The GBP value at receipt is added to your income and taxed at 20%, 40% or 45% depending on your total income.
2. Capital Gains Tax when sold: Any increase in value from receipt to sale is subject to CGT. The receipt value becomes your cost basis.

Example: Receive 0.1 ETH worth £200. Income tax: £80 (at 40%). Later sell for £300. CGT: £100 gain - £3,000 allowance = usually £0 additional tax.

HMRC requires detailed crypto records kept for at least 5 years (6 years from tax year end). You need:

• Date and time of every transaction
• Transaction type (buy, sell, trade, transfer)
• Amount of crypto and GBP value at transaction time
• Exchange/platform used and transaction fees
• Wallet addresses you own
• Evidence of cost basis (bank statements, exchange records)

Without records proving cost basis, HMRC can assume £0 cost = tax on entire proceeds. Download exchange CSVs regularly and use crypto tax software.

Yes! Crypto losses can offset gains to reduce your tax bill:

• Same tax year: Losses automatically reduce gains before the £3,000 allowance applies
• Carry forward: Unused losses carry forward indefinitely to offset future gains
• Must claim: You must actively claim losses on Self Assessment within 4 years

Example: £10,000 gain - £4,000 loss = £6,000 net - £3,000 allowance = £3,000 taxable. Tax-loss harvesting before April 5th is a key strategy.

FIFO (First-In-First-Out): Used in the USA - assumes you sell oldest crypto first. NOT valid for UK tax.

Section 104 Pooling: UK method - all purchases of same crypto pool together at average cost. Required by HMRC.

Example: Buy 1 BTC at £20k, then 1 BTC at £40k. Sell 1 BTC.

• FIFO: Cost = £20k (oldest first) - WRONG for UK
• Section 104: Cost = £30k (average of £20k + £40k) - CORRECT for UK

Using FIFO in the UK is non-compliant and usually results in paying more tax.

The tax treatment depends on the type:

• Hard forks: Generally NOT taxable when received (no acquisition cost). Taxable as CGT when later sold, with £0 cost basis.
• Airdrops: May be Income Tax if received in return for service/promotion. If unsolicited gift, may be £0 cost basis for CGT when sold.

The key question is whether you did anything to receive them. Marketing airdrops requiring social media posts may be treated as income.

You must file Self Assessment if:

• Crypto gains exceed £3,000 (even if no tax due after losses)
• Total disposal proceeds exceed £50,000 (even with small gains)
• You received crypto income (staking/mining) over £1,000
• You're already in Self Assessment for other reasons

Deadlines for 2025/26: Register by 5 October 2026, file online by 31 January 2027, pay tax by 31 January 2027.