Crypto and the SA108 Capital Gains Summary

In the UK, crypto capital gains are reported on the SA108 Capital Gains Summary — the supplementary page that goes with your SA100 Self Assessment return. CryptaTax produces your SA108-ready figures from your transaction history.

General information, not tax advice. Verify against current GOV.UK / HMRC guidance or a tax professional.

What is the SA108?

The SA108 is the Capital Gains Summary, filed alongside the main SA100 Self Assessment return. It's where you report disposals of chargeable assets — including crypto, which HMRC treats as property — with a dedicated cryptoassets section. You enter your disposals, proceeds, costs, and the resulting gains or losses, and apply the annual exempt amount (£3,000 for 2025/26).

How crypto goes on the SA108

For each token, you work out gains using HMRC's Section 104 pooling (an averaged cost), together with the same-day and 30-day matching rules. Those gains and losses are then reported in the cryptoassets section of the SA108. Two reporting triggers to remember:

• You must report if your net gains exceed the £3,000 allowance, or
• if your total disposal proceeds exceed £50,000 in the tax year — even if no tax is due.

The exact SA108 cryptoassets box numbers change by tax year — CryptaTax maps your figures to the current year's boxes. → Crypto tax in the UK →

Generate your SA108 figures with CryptaTax

Import your exchanges and wallets, and CryptaTax applies Section 104 pooling plus the same-day and 30-day rules automatically, then produces SA108-ready capital gains figures — and flags the £3,000 and £50,000 thresholds — ready for your Self Assessment or your accountant.

→ Import your exchanges & wallets →