CryptoTax UK · Guide
Using crypto losses to reduce your UK tax bill
If you've made a loss on a crypto disposal, HMRC may allow you to offset that loss against gains — potentially reducing your Capital Gains Tax bill significantly. This page explains how loss relief works in practice. Educational only — not tax advice.
Calculate my gains and losses →How loss offsetting works
Capital losses on crypto disposals may be offset against capital gains on any other chargeable asset disposals in the same tax year. If losses exceed gains in the year, the unused losses may be carried forward indefinitely to offset against future years' gains. You must formally claim losses via Self Assessment — they are not applied automatically.
Worked example: offsetting a loss
You sell BTC for a gain of £10,000 and sell ETH at a loss of £4,000 in the same tax year. Net gain: £6,000. After the £3,000 annual exempt amount, only £3,000 is taxable. At 18% (basic rate), CGT owed is £540. Without the loss relief, £7,000 would have been taxable — a saving of £1,260.
Carrying losses forward
Losses that cannot be used in the year they arise (because gains are already below the allowance, or there are no gains) may be carried forward to future tax years. You must still claim them on your Self Assessment return for the year in which they arose — within 4 years of the end of that tax year.
The bed and breakfast rule — a critical constraint
You cannot sell crypto to crystallise a loss and then immediately re-buy the same crypto within 30 days. HMRC's 30-day rule means the re-purchase replaces the disposal for matching purposes, neutralising the loss. Waiting 31 days before re-buying sidesteps this — but introduces price risk. Consider taking independent financial advice before implementing a loss harvesting strategy.
How to claim losses on Self Assessment
Claim losses on SA108 — specifically in the 'Losses in the year' and 'Losses available to be carried forward' boxes. The CryptoTax UK calculator calculates your net gains and losses automatically and outputs the exact SA108 figures.
Frequently asked questions
Can I claim losses on crypto that has gone to zero?
Possibly, via a negligible value claim. If a cryptoasset has become worthless (e.g. an exchange collapsed), you may be able to make a claim to HMRC to be treated as having disposed of it at nil value, crystallising the loss. Specific rules apply — consider speaking to a qualified accountant.
Do I need to report losses even if I have no gains?
Yes, if you want to carry the losses forward. You must claim them on Self Assessment within 4 years of the end of the tax year in which they arose. Unclaimed losses cannot be used in later years.
Can I offset crypto losses against income tax?
Generally no — capital losses on crypto can only be offset against capital gains, not against income. There is a limited exception for losses on qualifying Enterprise Investment Scheme shares, but this does not typically apply to crypto.
What if my losses are in a different tax year from my gains?
Carry-forward losses may offset gains in future years after using the current year's annual exempt amount. The order of set-off is: current year losses first, then brought-forward losses. The £3,000 allowance is applied after all loss relief.
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Calculate my gains and losses →Educational guidance only. CryptoTax UK is not a regulated tax adviser and the information above does not constitute tax, legal or financial advice. Always confirm your specific position with HMRC or a qualified accountant before filing.