UK Crypto Tax 2026: HMRC Rules, Annual Exemption, and SA108 Explained

If you hold crypto in the UK, one question matters above all others: when does HMRC want its cut? The short answer is almost every time you dispose of a cryptoasset — sell it, swap it, gift it, or spend it. Understanding UK crypto tax means understanding how HMRC classifies your holdings, what the annual Capital Gains Tax (CGT) exemption still covers, and how to correctly complete the SA108 supplementary pages on your Self Assessment return.

This guide covers the core rules as set out in the HMRC Cryptoassets Manual, with practical examples for retail traders, DeFi users, and anyone receiving staking income or airdrops.

How HMRC Classifies Cryptoassets

HMRC does not treat Bitcoin, Ether, or any other cryptoasset as currency or money. According to the HMRC Cryptoassets Manual, most tokens held by individuals are classified as a capital asset — meaning that gains realised on disposal are subject to Capital Gains Tax, not income tax.

This approach is broadly consistent with how other major jurisdictions treat crypto. The Australian Tax Office similarly considers crypto a capital asset under its guidance, and the IRS has treated virtual currency as property since Notice 2014-21. Germany, by contrast, offers a longer-term exemption — gains on crypto held for more than one year are generally tax-free there, making it a notable outlier in the European landscape alongside jurisdictions like Portugal (though Portuguese policy has evolved significantly) and the UAE.

In the UK, there is no equivalent long-hold exemption. The holding period does not reduce your CGT liability. What matters is the amount of gain, not how long you held the asset.

What Counts as a Disposal Under UK Crypto Tax Rules?

HMRC's Cryptoassets Manual lists the following as taxable disposal events:

• Selling crypto for fiat (e.g., selling ETH for GBP)
• Swapping one token for another (e.g., swapping ETH for USDC — this is a disposal of ETH at market value)
• Spending crypto on goods or services
• Gifting crypto to anyone other than a spouse or civil partner
• Transferring crypto to a spouse or civil partner is generally not a disposal — it transfers at a no-gain/no-loss basis

Simply moving crypto between your own wallets — for example, from a Coinbase account to a hardware wallet — is not a disposal, provided you can demonstrate both wallets belong to you.

Section 104 Pooling: How Cost Basis Works in the UK

One of the most misunderstood aspects of UK crypto tax is the Section 104 pool (also called the share pool). Unlike the US, where you can often elect FIFO, LIFO, or HIFO cost basis methods, UK individuals must use the pooling method as set out in HMRC's guidance.

Under this approach, all units of the same token are treated as a single pooled asset. When you acquire more, the total cost is added to the pool. When you dispose of some, you calculate the proportion of the total pool cost that relates to the units sold. The result is an average cost basis — you cannot cherry-pick specific lots.

Example: You buy 2 ETH at £1,000 each (pool cost: £2,000), then 2 more ETH at £2,000 each (pool cost rises to £6,000). You later sell 1 ETH for £3,000. Your allowable cost is £6,000 ÷ 4 = £1,500. Your gain is £3,000 − £1,500 = £1,500.

There are two important override rules layered on top of Section 104 pooling:

1. Same-day rule: If you buy and sell the same token on the same day, those acquisitions are matched first against that day's disposals.
2. Bed and breakfasting rule (30-day rule): If you sell a token and repurchase the same token within 30 days, the repurchase is matched against the sale — not pooled. This prevents you from realising a loss artificially and immediately buying back in.

These rules make the UK's cost basis system more complex than it first appears, particularly for active DeFi users who may be making dozens of swaps a week. Tools that handle DeFi tax reporting automatically — including the Section 104 pool recalculation, same-day matching, and 30-day lookback — can save significant time and reduce the risk of errors.

The Annual CGT Exemption: What It Covers (and What It No Longer Covers)

Every UK individual has an Annual Exempt Amount for CGT. In recent years, HMRC has substantially reduced this threshold — it stood at £12,300 for 2022/23, was cut to £6,000 for 2023/24, and fell further to £3,000 for 2024/25 onwards. This means a far greater share of crypto gains are now taxable compared to just a few years ago.

If your total net capital gains across all assets (crypto, shares, property) fall below the annual exempt amount for the tax year, you generally owe no CGT and do not need to report those gains on a Self Assessment return — though reporting thresholds and rules can be complex, and HMRC's guidance should be consulted for your specific situation.

CGT rates on cryptoassets for individuals currently sit at 18% (basic rate taxpayer) and 24% (higher or additional rate taxpayer), applied to gains above the exempt amount. These rates reflect the 2024 Autumn Budget changes and apply to crypto as a non-residential property asset. Always verify current rates with HMRC, as Budgets can alter these figures.

When Crypto Is Taxed as Income Instead

Not all crypto receipts are capital gains. HMRC's Cryptoassets Manual draws a clear line: some activities generate income, and those receipts are subject to Income Tax and National Insurance instead of CGT.

Activities HMRC generally treats as income-generating include:

• Mining rewards — if mining is carried out as a trade, receipts are trading income; if occasional, they may be miscellaneous income
• Staking rewards — typically treated as miscellaneous income at the fair market value on the date of receipt
• Airdrops received in return for a service — taxed as income; unsolicited airdrops with no conditions may sometimes escape income tax but are still subject to CGT on disposal
• DeFi lending interest and liquidity mining rewards — HMRC's guidance acknowledges the complexity here; the nature of the return (loan interest vs. new tokens) affects treatment

The Income Tax treatment is important to note because it feeds into your Self Assessment calculation separately from your capital gains — and the rates are meaningfully higher (up to 45% for additional rate taxpayers, versus 24% CGT).

How to Report: SA108 Capital Gains Summary

If you have taxable crypto gains (or losses you want to register with HMRC), you report them on the SA108 Capital Gains Summary supplementary pages, which form part of the annual Self Assessment tax return.

The SA108 requires you to report:

• Total proceeds from disposals
• Total allowable costs (your pooled cost basis)
• Net gains or losses for the year
• The annual exempt amount applied
• Any losses brought forward from prior years

You do not need to list each individual trade on SA108 itself — but HMRC may request detailed transaction records if they open an enquiry. Keeping a full transaction log (timestamps, GBP value at disposal, cost basis, gain/loss per trade) is strongly advised. The Self Assessment deadline for online filing is 31 January following the end of the tax year (which runs 6 April to 5 April).

If you only have crypto income (staking rewards, for instance) and no capital gains, that income is reported in the Other UK income section of your main SA100 return, not on SA108.

Crypto Tax Loss Harvesting in the UK

One often-overlooked advantage of the UK system: capital losses are valuable. If you realise a loss on a crypto position, that loss can be:

• Offset against gains in the same tax year, reducing your net taxable gain
• Carried forward indefinitely to offset gains in future years, if losses exceed gains in the current year

The 30-day bed and breakfasting rule (described above) prevents you from selling purely to crystallise a loss and immediately repurchasing the same token. But if you sell a loss-making position and wait 30 days before buying back — or swap into a correlated but distinct asset in the meantime — the loss is generally allowable.

This is a genuine planning opportunity that active DeFi participants often miss. Reviewing your unrealised positions before 5 April each year can meaningfully reduce your tax bill.

UK vs. Other Jurisdictions: A Quick Snapshot

For context, it's worth noting how the UK approach compares internationally. Australia's ATO applies a 50% CGT discount for assets held longer than 12 months — something UK residents don't benefit from. Germany's one-year exemption for private sales means long-term holders can realise gains entirely tax-free. Portugal, once a crypto haven, introduced a 28% CGT on short-term holdings in 2023. The UAE remains one of the few jurisdictions with no personal income or capital gains tax at all.

These differences matter if you're considering relocation or structuring international activity. Tax residency rules are complex, and simply holding assets on a foreign exchange does not change your UK tax obligations if you remain UK-resident.

Practical Takeaways for UK Crypto Holders in 2026

• Every swap is a disposal. Don't assume DeFi activity is invisible to HMRC — the Cryptoassets Manual explicitly addresses token exchanges, LP positions, and staking.
• The £3,000 annual exemption is small. Even modest crypto gains can push you into taxable territory. Track every transaction from day one.
• Section 104 pooling is mandatory. You cannot cherry-pick lots. Your crypto tax software must implement pooling correctly — including the 30-day and same-day matching rules.
• Losses are assets. Register losses with HMRC even in years when you have no gains, so they're available to carry forward.
• Income vs. capital matters. Staking rewards are likely income at receipt, but they also have a cost basis for CGT purposes when you eventually sell them.

Navigating these rules across hundreds of on-chain transactions — across protocols like DeFi platforms, CEXs, and staking providers — is where automated tax tools earn their keep. Software that understands UK-specific rules (Section 104 pooling, the 30-day rule, income vs. capital classification) removes the manual calculation burden and helps you generate the records HMRC expects to see. If you're comparing options, our crypto tax software guide covers the main tools available to UK users.