UK Tax on Bitcoin Sports Betting Winnings: CGT, Income Tax and HMRC

The HMRC letter I never received and the one a friend did

A friend of mine who’d been betting NBA in crypto for two years got a casual nudge from HMRC in 2024 – not a formal investigation, just a query about cryptoasset disposals across the previous tax year. He’d never converted his sportsbook winnings to GBP. He hadn’t filed anything related to crypto. HMRC had matched data from a UK exchange that he’d used to buy his original BTC. The question wasn’t about his betting. It was about the underlying cryptoasset that the betting wins had compounded.

The UK’s tax treatment of crypto-denominated sports betting sits at an awkward intersection of two regimes. Gambling winnings are not taxable income in the UK. Cryptoasset disposals are taxable as Capital Gains Tax events. When you bet in BTC and win in BTC, you’ve created a tax footprint even though no GBP has changed hands. Approximately 8% of UK adults – about 4.5 million people – owned crypto in 2024, with an average portfolio value of £1,842. The HMRC infrastructure for tracking those holdings is more sophisticated than most casual punters realise.

This guide covers the gambling tax position, why the crypto asset itself remains chargeable, CGT mechanics, the record-keeping that protects you, the professional-versus-amateur question, and what HMRC actually expects on a self-assessment return.

I’m not a tax adviser; this is practitioner observation, not legal or financial advice. Anyone with material crypto-betting activity should engage a qualified accountant for their specific situation.

Why gambling itself isn’t taxed in the UK

The UK has long held that gambling winnings are not subject to income tax for ordinary bettors. The reasoning sits in HMRC’s general principle: gambling is not a trade in the legal sense for most people, and the wins are considered windfalls. Whether you bet on horses, football, or NBA point spreads, the wins themselves don’t appear on your tax return as income.

That principle is well-settled. It applies whether the bet is placed in GBP through a UK-licensed bookmaker, or in BTC through an offshore crypto sportsbook. The act of betting and winning is not what creates the tax liability for the recreational punter. This is a meaningful difference from many other jurisdictions where gambling winnings are taxable income.

The principle has a limit. If gambling becomes systematic enough to constitute a trade – a sustained, businesslike activity with the intent of generating income – HMRC can treat it as a trade and tax the income. The threshold for this treatment is high in practice; most active recreational punters never approach it. We’ll come back to this distinction in the professional-versus-amateur section below.

But the crypto asset itself is chargeable

The structural feature that creates UK tax exposure for crypto bettors is that HMRC treats cryptoassets as chargeable for Capital Gains Tax purposes. Disposing of a cryptoasset – selling it, swapping it, spending it, or using it in any way that transfers it – is a CGT event. The gain or loss is calculated relative to your acquisition cost.

Placing a sports bet in BTC is a disposal of cryptoasset at the moment the bet is placed. The “consideration” you receive is the betting position. If your BTC has appreciated since you acquired it, you’ve realised a capital gain at the moment of the bet. The basketball outcome that follows is the gambling event, but the underlying disposal has already happened.

Winning the bet returns BTC to your sportsbook balance. That BTC, when subsequently withdrawn or used, is a fresh acquisition with a new cost basis equal to the value at the time of receipt. The chain of CGT events continues as long as you remain active in crypto. The gambling outcome influences the size of your BTC balance, but the asset itself is subject to CGT throughout.

Tim Miller, the UK Gambling Commission’s Executive Director of Research and Policy, said at the BGC AGM 2026 about the FCA’s incoming cryptoasset regime: “Firms wishing to undertake any of the new cryptoasset regulated activities will need to be authorised by the FCA under FSMA with permission to undertake those activities at the point the new regime commences.” That regulatory framework, commencing 25 October 2027, creates the structure under which crypto-asset gambling can eventually be UK-licensed. The CGT treatment of underlying crypto holdings will not change just because gambling becomes UK-licensed – the chargeability of the asset is a separate matter from the regulation of the activity.

How CGT mechanics actually apply to a betting punter

Each individual has an annual CGT allowance – £3,000 for the 2025-26 tax year, down from £6,000 in 2024-25 and £12,300 in 2023-24. Gains within the allowance are not taxed. Gains above are taxed at 10% or 18% (basic-rate) or 20% or 24% (higher-rate) depending on your other income and the type of asset.

The “pool” rules for cryptoassets in the UK treat all units of the same cryptocurrency as a single pool with a weighted-average cost basis. When you dispose of any BTC, the cost basis is the pool average at the moment of disposal, not the cost of any specific coin. This simplifies record-keeping but requires that you maintain a single running balance and cost basis.

For a betting punter, the practical implications are significant. Every bet is a partial disposal of your BTC pool. The gain or loss on each bet is calculated relative to the pool average. If you bet 0.01 BTC when your pool average is £20,000 per BTC and the spot price is £30,000 per BTC, you’ve realised £100 of capital gain on that bet placement, regardless of whether the bet wins or loses.

Across a year of active betting, the cumulative number of disposals can be substantial. A punter placing 500 bets a year is creating 500 CGT events. The gains and losses on each event aggregate to a net annual figure that gets compared against the £3,000 allowance. Most active crypto bettors with appreciated holdings exceed the allowance, triggering a CGT liability that the underlying gambling activity didn’t create but didn’t prevent either.

Record-keeping that protects you

HMRC’s expectation for cryptoasset record-keeping is comprehensive. For each acquisition: date, quantity, asset, cost basis in GBP at time of acquisition, source. For each disposal: date, quantity, asset, value in GBP at time of disposal, counterparty or transaction reference. The records need to be maintained for at least five years from the relevant tax year’s filing deadline.

For a betting punter, that means logging every deposit to a sportsbook (acquisition by the sportsbook, but disposal from your wallet), every bet placed (movement within the sportsbook system, though most accountants would treat the wallet-to-sportsbook movement as the relevant disposal), every withdrawal back to your wallet (acquisition at the withdrawal time and rate), and any conversions between crypto types.

The practical approach most active punters use: maintain a spreadsheet logging deposits and withdrawals at GBP-equivalent values from a public rate source. The within-sportsbook activity isn’t separately tracked at the bet level; HMRC’s interest is in the disposal from your control to the sportsbook (deposit) and the acquisition back to your control (withdrawal), not in every individual bet placed.

That treatment isn’t universally agreed; some tax advisers argue every bet placement is a disposal because the BTC moves from your effective control to the bookmaker’s risk position. The conservative interpretation is to treat each bet as a separate disposal; the practical interpretation that most experienced advisers seem to use treats deposits and withdrawals as the relevant events. HMRC has not published definitive guidance specific to crypto-denominated sports betting, which leaves the question genuinely ambiguous for now.

Professional versus amateur: the question that matters more than most realise

HMRC’s “badges of trade” test determines whether activity is a trade for tax purposes. The test considers factors like frequency, organisation, profit motive, the way the activity is conducted, and whether it has the character of a business.

For sports betting, the threshold is high. Even punters making sustained profit across multiple years are typically not treated as trading. Case law generally treats betting as gambling unless the activity has dramatically organised commercial character – say, employing staff, taking on debt to fund positions, or treating the activity as a full-time occupation with business infrastructure.

The relevant interaction for the crypto punter: even if your betting is recreational and non-trading, your crypto-asset disposals are still CGT events. Trading status would convert your gambling income to taxable income, but the CGT treatment of your crypto disposals doesn’t depend on trading status. The £3,000 CGT allowance applies whether you bet weekly or daily, professionally or recreationally.

The honest threshold most casual UK crypto punters need to worry about: their CGT-allowance position. A trader status concern only arises if betting becomes the primary source of income, the activity has the character of a business, and HMRC has reason to scrutinise. For most readers, the conservative approach is to assume amateur gambling status (which is favourable for income tax) and chargeable cryptoasset status (which creates the CGT obligation).

What goes on the self-assessment return

UK self-assessment requires reporting of CGT events when total gains exceed the annual allowance or when total proceeds from disposals exceed four times the allowance (£12,000 for 2025-26). For an active crypto punter, the proceeds test almost always triggers reporting, even when the actual gain is within the allowance.

The cryptoasset section of the self-assessment requires aggregate figures: total proceeds, total cost basis, total gain or loss, and any allowable losses carried forward. The supporting calculations need to be retained but typically aren’t submitted with the return itself.

For winnings on the sportsbook side, no separate reporting is required because gambling winnings are not taxable income for amateur status. The two regimes are entirely separate on the return: gambling is invisible, cryptoasset activity is visible.

One practical wrinkle: some crypto exchanges report user data to HMRC under existing reporting frameworks. An exchange you used to buy your original BTC may have submitted your trading data to HMRC. If you’ve subsequently moved that BTC to a sportsbook and back, the chain of custody is visible from the exchange’s side. HMRC matching exercises across this data have intensified through 2024 and 2025, which is the context for the casual nudge letters my friend received.

The broader UK regulatory framework for crypto gambling – including which operators can serve UK customers and what protections exist – sits alongside the tax question. The legal landscape for crypto basketball betting in the UK is covered comprehensively in our UK crypto gambling legality breakdown, including how the 2027 FCA commencement will reshape the operator side of the equation.

What I do with my own records

The routine: every deposit to a sportsbook gets logged with date, BTC amount, GBP-equivalent at the time of transaction, and the destination address. Every withdrawal back is logged with the same fields. I keep the records in a simple spreadsheet I update weekly during the season, not the calendar year-end rush. The discipline is to maintain rather than reconstruct – reconstruction is harder than maintenance, and HMRC’s expectation is that you have records, not that you can recreate them.

The other discipline: every year I calculate my annual CGT position before the tax year ends, not after. If I’m close to the allowance, I make strategic decisions about whether to realise additional gains or losses before the year ends. The £3,000 annual allowance – reduced from £12,300 over the last two years – makes this matter for more punters than it used to.

The honest summary: gambling is tax-free, the underlying crypto is chargeable, records protect you, and the regulatory environment is moving fast enough that a qualified accountant is worth the fee for meaningful activity. HMRC’s approach has tightened, the data they receive has expanded, and the post-2027 environment will likely include further changes to both regimes.

Prepared by the Bitcoin Basketball Bets editorial staff.