How to Report Crypto to HMRC for the 2025/26 Tax Year
The 2025/26 Capital Gains Tax summary contains dedicated cryptoasset boxes. This guide explains when SA108 is needed, entries in boxes 13.1 to 13.8, crypto income and the filing deadlines for the 2025/26 return.
Reviewed October 9, 2026. This guide covers the UK tax year from 6 April 2025 to 5 April 2026, reported after the year ends. It does not assume that every person who owns crypto must file a return. It explains how to decide, how to assemble the figures and how the dedicated crypto section structures the filing workflow; HMRC says a separate crypto section has been available since the 2024/25 return.
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Start for free →Ownership alone is not a filing trigger. Start by separating disposals, taxable receipts and non-taxable movements. For 2025/26, HMRC's official SA108 notes say to complete the Capital Gains Tax summary if, among other cases:
- chargeable assets disposed of during the year were worth more than £50,000;
- chargeable gains before deducting losses were more than the £3,000 annual exempt amount;
- you want to claim an allowable capital loss, relief, claim or election;
- gains from an earlier year become taxable in this period;
- a relevant foreign income and gains regime or property rule applies.
The £50,000 test concerns the value of chargeable assets disposed of, not profit and not an automatic tax-free limit. A person can have no tax to pay but still need SA108. Conversely, a person below those tests may still need a return because of crypto income, self-employment or unrelated income. Use the UK crypto rate and allowance guide to calculate the taxable amount separately from the reporting test.
For non-trading mining, staking, lending and certain DeFi receipts, HMRC currently says total miscellaneous income from all sources between £1,000 and £2,500 should be raised with HMRC, while over £2,500 requires Self Assessment registration. The trading and miscellaneous income allowance is shared across relevant sources, not a separate £1,000 crypto allowance.
Prepare one sterling transaction ledger before filing
Do not begin with the tax-return boxes. First reconcile all exchanges and wallets. Duplicate imports, missing transfers and fees represented as separate transactions can distort proceeds and pools. A complete workflow is:
- Download full histories from every exchange, wallet and protocol.
- Identify beneficial-owner transfers so they are not treated as sales.
- Value every disposal and taxable receipt in pounds at the relevant time.
- Classify sales, token swaps, spending, gifts, rewards and DeFi events.
- Apply same-day and 30-day matching before the section 104 pool.
- Calculate total proceeds, allowable costs, gains and losses.
- Reconcile ending token quantities to wallet and exchange balances.
- Preserve the detailed computation that supports the return totals.
HMRC requires computations and details of each gain or loss alongside SA108. A summary total without an audit trail is not a substitute for transaction-level calculations.
How to complete the SA108 cryptoasset section
The official SA108 for 2025/26 has a dedicated “Cryptoassets” section. This is a meaningful change from treating ordinary crypto disposals only within a generic other-assets section.
| Box | Entry | Source from your report |
|---|---|---|
| 13.1 | Number of disposals | Count under HMRC matching rules |
| 13.2 | Disposal proceeds | Gross sterling proceeds before reliefs |
| 13.3 | Allowable costs | Purchase price and qualifying costs |
| 13.4 | Gains before losses | Total positive gains, with relevant adjustments |
| 13.5 | Losses in the year | Total allowable crypto losses |
| 13.6 | Claim or election code | Only the applicable official code |
| 13.7 | Real Time gains or losses | Amounts already reported using that service |
| 13.8 | Tax already paid | Tax paid on box 13.7 gains |
Do not enter the net gain in every box. Boxes 13.4 and 13.5 preserve gross positive gains and losses separately. The annual exempt amount and brought-forward losses are dealt with in the wider CGT calculation.
Three disposals: one net gain is not enough for the form
Assume three separate, fully matched disposals, with allowable costs already including qualifying fees and no Real Time return or special election:
| Disposal | Proceeds | Allowable cost | Result |
|---|---|---|---|
| A | £8,000 | £7,000 | £1,000 gain |
| B | £2,000 | £2,400 | £400 loss |
| C | £6,000 | £5,500 | £500 gain |
The example supplies count 3 in 13.1, £16,000 proceeds in 13.2, £14,900 costs in 13.3, £1,500 positive gains in 13.4 and £400 losses in 13.5. The £1,100 net result is a check, not the entry in every box. With the normal £3,000 AEA and no other gains, CGT is nil, but claiming the allowable loss still requires the appropriate claim and computation.
At this review date, 9 October 2026, the 5 October registration date has passed. If newly required and unregistered, register promptly and follow HMRC’s notified filing date. Late registration does not move the 31 January 2027 payment deadline. Save the submitted computation and HMRC receipt.
Where staking, mining, employment and DeFi income goes
SA108 covers capital disposals, not every crypto receipt. Tokens received from employment can be earnings, and non-trading mining, staking or lending rewards are commonly other taxable income at their sterling value on receipt. Trading receipts belong in the relevant trading pages. A later sale can then produce a separate CGT result using the value already taxed as income where the legislation permits.
DeFi cannot safely be mapped by event label alone. HMRC's manual distinguishes a return for providing a service, often revenue, from growth realised through disposal of a capital asset. The contract, beneficial ownership, agreed return, periodicity and economic substance matter. See the UK staking and DeFi guide for the classification questions.
2025/26 Self Assessment deadlines
| Action | Deadline |
|---|---|
| Tell HMRC you need a return, if newly required | 5 October 2026 |
| Paper return | 31 October 2026 |
| Online return | 31 January 2027 |
| Pay Self Assessment balance | 31 January 2027 |
| Request payment through tax code, if eligible | 30 December 2026 |
These dates are confirmed by HMRC's 2025/26 deadline page. Late registration can produce a separate three-month filing date, but tax is still due by 31 January 2027.
Self Assessment versus the Real Time CGT service
A UK resident can use HMRC's Real Time service for eligible non-property gains during or after the tax year. For a 2025/26 gain, the service deadline is 31 December 2026 and payment is due by 31 January 2027. If already registered for Self Assessment, the gain must also be included in the return; SA108 boxes 13.7 and 13.8 prevent the previous report and tax payment from disappearing.
Self Assessment is normally the clearer route where there are many exchanges, losses, crypto income or other return obligations. Do not submit the same payment twice.
What crypto records should be kept?
HMRC places responsibility on the individual, even if an exchange closes or retains only short history. Its record-keeping manual calls for token type, transaction date, purchase or sale, units, sterling value, cumulative units, bank statements and wallet addresses. Retain:
- raw CSV/API exports and statements from every platform;
- wallet addresses, transaction hashes and evidence of beneficial ownership;
- sterling valuation sources and timestamps;
- section 104 pool, same-day and 30-day calculations;
- fee treatment, income classification and DeFi agreements;
- the filed return, attached computation and HMRC correspondence.
What CARF changes—and what it does not
UK CARF obligations began on 1 January 2026 for in-scope reporting cryptoasset service providers. They collect customer and transaction data for calendar year 2026 and the first reports are due by 31 May 2027. This does not mean every 2025/26 transaction was automatically reported through CARF, and it does not postpone a taxpayer's filing duty.
The official HMRC commencement guidance gives the exact dates. Read the UK CARF guide for provider scope and user data.
HMRC crypto reporting FAQ
Must everyone who bought crypto file Self Assessment?
No. Buying or holding alone is not the test. Review disposals, gains, income, loss claims and all other return obligations.
Do I report each trade separately on the face of SA108?
SA108 contains aggregate boxes, but HMRC instructs taxpayers to enclose computations with details of each gain or loss.
Does a £50,000 proceeds total mean £50,000 tax?
No. It is a reporting test in the 2025/26 SA108 notes, not profit or tax due.
Will CARF calculate my UK tax?
No. Providers report standardised data; the taxpayer still applies UK classification, sterling valuation, pooling and relief rules.
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Start for free →Disclaimer: This article is for general informational purposes only and does not constitute tax advice. For individual tax advice, consult a licensed tax professional.