Which UK tax form for crypto? SA100, SA108 and SA106 explained (2026)

Self Assessment is modular. You file the main SA100 return, then attach supplementary pages for the parts of your finances that need them. For crypto, the question is which supplementary pages apply. This guide covers the four forms most commonly involved — SA100, SA108, SA106 and SA110 — and tells you exactly which boxes your crypto figures land in.

Which forms in 30 seconds

• SA100 — main return, declares income (including staking rewards).
• SA108 — Capital Gains Summary, where every taxable disposal lands.
• SA106 — foreign income, only if relevant (rare for crypto).
• SA110 — tax calculation summary, paper filers only.

SA100 — the main return

SA100 is the wrapper. It collects your personal details, employment income, pension, savings interest, dividends, and any miscellaneous income. For crypto specifically you care about two things on SA100:

• The CGT trigger boxes (page TR2).A series of yes/no questions, including "If you disposed of any chargeable assets, do you need to complete the Capital Gains Summary page?". Tick yes if your gains exceeded the £3,000 annual exempt amount, or proceeds exceeded £50,000, or you want to claim a loss.
• Other UK income (page TR3).Staking, lending interest and rewarded airdrops go in box 17, with a description like "Cryptoasset staking rewards". The £ value goes in the amount box.

Online, the system generates SA100 from your answers. On paper, you tick the boxes manually and the figures flow onto SA110 for the tax calculation.

SA108 — Capital Gains Summary

SA108 is where crypto disposals belong. The form has separate sections for residential property, listed shares, unlisted shares, and other property, assets and gains. Crypto sits in the "Other property, assets and gains" block — boxes 14 to 22 on the 2025/26 paper version.

You also attach a computation: a one-page schedule listing every disposal with date, asset, quantity, proceeds, allowable cost and gain or loss. Most software produces this PDF automatically — see our software roundup for tools that map cleanly to the SA108 boxes.

SA106 — foreign income

SA106 trips up a lot of crypto holders, but in nearly every case it does not apply. HMRC's position is that cryptoassets are situated where the beneficial owner is resident, so for a UK-resident investor crypto is not foreign property. You file gains on SA108 regardless of whether your tokens lived on Binance, a Ledger or a US exchange.

SA106 is only relevant in narrower cases:

• You are non-domiciled and electing the remittance basis — gains on assets situated outside the UK can fall on SA106 instead of SA108.
• You have foreign-sourced staking or interest income paid in crypto by an offshore platform that issued a tax certificate.
• You are claiming foreign tax credit relief because another jurisdiction has already taxed the same income.

If you live in the UK on the arising basis (which is the default for the vast majority of residents), skip SA106.

SA110 — tax calculation summary

SA110 is where the tax owed gets totted up. Online filers never see this form — the HMRC online service does the maths and shows you a result page. Paper filers must complete SA110 manually using the figures from SA100, SA108 and any other supplementary pages.

For crypto on paper, the relevant lines on SA110 are the income tax due (which absorbs your staking rewards via SA100 box 17) and the CGT due (which uses the SA108 totals). The HMRC SA110 notes walk through the calculation; see gov.uk SA110 guidance.

Where staking and mining go (and don't)

It is worth restating because it is the most common mistake we see: staking, mining and lending income do not belong on SA108. They are income, taxed at your marginal rate (20% / 40% / 45%), and reported on the main SA100. Box 17 of page TR3, with a free-text description, is the standard place.

When you later sell those staked tokens, the disposal goes on SA108 with the cost basis equal to the £ value at the date of receipt — the same number you already declared as income.

Online filing vs paper

Almost every crypto filer should use the HMRC online service. The advantages are concrete:

• Deadline is 31 January (rather than 31 October) following the tax year.
• SA110 is generated automatically — no manual tax calculation.
• You can attach computation PDFs directly to your return.
• Refunds are processed faster.

For a complete walkthrough of the online process, see our step-by-step Self Assessment guide. If you are not sure whether you need to file at all, start with do I have to report crypto?.