Crypto Tax Calculator

How does HMRC tax crypto?

HMRC treats cryptocurrency as a chargeable asset, not currency. Most activity falls under Capital Gains Tax (CGT). Some — staking, mining rewards, airdrops — is taxed as income at the value when received.

"Disposal" includes more than just selling for fiat:

• Selling crypto for GBP/USD
• Swapping one crypto for another (e.g. BTC → ETH)
• Spending crypto on goods/services
• Gifting crypto (except to a spouse)

How crypto CGT is calculated

UK rules require Section 104 pooling — you can't pick which "lot" of a coin you sold. All your holdings of each coin are pooled at average cost. Three matching rules apply in order:

1. Same-day rule — disposals matched against acquisitions on the same day
2. 30-day rule ("bed-and-breakfast") — disposals matched against acquisitions in the next 30 days
3. Section 104 pool — everything else uses average cost

2025/26 annual exempt amount £3,000. Rates: 18% basic / 24% higher (since October 2024).

When and how to report

• Self Assessment SA108 — annual report of all gains, due 31 January
• Threshold — only required if total gains exceed £3,000 OR proceeds exceed £50,000
• Income from staking/mining/airdrops — declare on SA in the year of receipt at GBP value
• HMRC has data — exchanges share data with HMRC under the Crypto-Asset Reporting Framework (CARF), being rolled out 2026+

Crypto tax planning

• Use the £3,000 annual exempt amount every year — sell up to that gain tax-free
• Realise losses in the same year to offset gains
• Spousal transfers — pre-disposal transfers use both allowances
• Hold longer — no UK long-term capital gains rate, but ISA-wrapping equivalent assets is tax-free
• Tools that help — Koinly, Recap, CoinTracking handle Section 104 automatically