# Crypto capital losses in the UK — claiming and carrying forward

Crypto capital losses offset gains in the same tax year. Unused losses carry forward to future years. Report losses on SA108 box 13.5. You cannot claim income tax relief for capital losses on personal investments. Lost or stolen crypto may still be a disposal — evidence is essential.

## Key facts
- Losses must be claimed — they are not automatic.
- Same-year losses offset same-year gains first.
- Carry forward indefinitely until used.
- Negligible value claims possible if asset becomes worthless.
- Bed and breakfast rules limit artificial loss creation.

## Calculating a capital loss

Loss = allowable cost (pool) minus disposal proceeds. Selling bitcoin below your pooled average creates a loss even if you still hold other tokens.
## Using losses in the tax year

Net losses against net gains. If overall net loss, no CGT due — report the loss on SA108 to preserve carry forward.
## Carrying forward

Unused losses roll to future tax years and offset future gains. Keep SA108 submissions as proof.
## Lost, stolen or worthless tokens

HMRC may accept negligible value claims or theft disposals with evidence — police reports, exchange confirmations. Complex cases need professional advice.
## Tax-loss harvesting caution

Selling to crystallise a loss then rebuying within 30 days triggers bed-and-breakfast matching — the loss may not work as expected. Wait 31 days or buy a different asset.

## FAQs
### Can I offset crypto losses against salary?

No. Capital losses offset capital gains only, not Income Tax on employment.

## Sources

- [HMRC — Capital Gains Tax losses](https://www.gov.uk/capital-gains-tax/losses)
- [HMRC — Cryptoassets Manual](https://www.gov.uk/hmrc-internal-manuals/cryptoassets-manual)

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— Digital Assets UK (https://digital-assets.co.uk/tax/crypto-losses-and-harvesting/), reviewed 2026-06-23. Source: https://www.gov.uk/capital-gains-tax/losses