Free UK Crypto Tax Calculator

In the UK, HM Revenue & Customs (HMRC) treats cryptocurrency as a chargeable asset for Capital Gains Tax (CGT) purposes. When you dispose of crypto — by selling it for fiat, exchanging it for another crypto, or using it to buy goods or services — you may realise a gain or loss that needs to be reported.

Annual Exempt Amount. Every individual has a tax-free allowance of £3,000 for the 2025/26 tax year (reduced from £6,000 in 2023/24). Only gains above this threshold are subject to CGT. If your total gains are below £3,000, you owe no CGT.

Crypto CGT rates. Unlike most chargeable assets (which are taxed at 10% and 20%), cryptocurrency disposals are taxed at higher rates: 18% for basic-rate taxpayers and 24% for higher- and additional-rate taxpayers. The rate depends on how much of your basic-rate band remains after accounting for your other income.

Calculating your rate. First, deduct your personal allowance (£12,570 for 2025/26) from your annual income to find how much of the basic-rate band (£50,270) you have used. Any remaining basic-rate band is taxed at 18%. Gains that exceed the remaining basic-rate band are taxed at 24%.

Bed & Breakfast rule. If you sell crypto and buy the same (or substantially identical) asset back within 30 days, the cost basis for the original sale is matched to the repurchase price. This "same-day and 30-day rule" prevents investors from selling to crystallise a loss and immediately rebuying. Use Section 104 pooling (average cost) for disposals outside the 30-day window.

Losses. Capital losses can be offset against gains in the same tax year, and any unused losses can be carried forward indefinitely. You must report losses to HMRC within four years to carry them forward.

Cost basis pooling (Section 104). HMRC requires you to pool the cost of all identical crypto assets you hold into a single pool, known as a Section 104 pool. Your allowable cost for each disposal is calculated using the average cost of all units in the pool. This means you cannot specifically identify which units you are selling to reduce your gain. The same-day rule and 30-day bed-and-breakfast rule take priority over the Section 104 pool.

Income from crypto activity. Not all crypto income is subject to CGT. Mining, staking, and airdrop rewards are typically treated as income and subject to Income Tax and National Insurance contributions. Crypto received from employment is taxed as employment income. When you later dispose of crypto received as income, the fair market value at the time of receipt becomes your cost basis for CGT purposes.

Reporting to HMRC. You must report crypto gains or losses on your Self Assessment tax return if your total gains exceed the Annual Exempt Amount, or if you have losses you wish to carry forward. You must register for Self Assessment by 5 October and submit your return by 31 January following the end of the tax year. HMRC expects you to keep detailed records of all crypto transactions for at least four years.