Gambling Tax Exemption (UK)

The United Kingdom does not tax gambling winnings for individuals. Under HMRC's long-standing position, betting and gambling profits are not subject to income tax or capital gains tax — the tax burden falls on the operators instead (via the Remote Gaming Duty and other licensing fees).

Prediction markets and the UK exemption

Whether prediction market profits qualify for the gambling exemption depends on how HMRC classifies them:

• If gambling/betting: Profits are completely tax-free. Losses cannot be offset against other income.
• If financial instruments: Profits are subject to Capital Gains Tax (CGT) at 10% (basic rate) or 20% (higher rate), with a £3,000 annual exemption (2024/25).
• If trading: Profits may be subject to income tax at marginal rates.

The Gambling Commission factor

Platforms licensed by the UK Gambling Commission (which could include some prediction market operators) have a stronger argument for gambling treatment. U.S.-regulated platforms like Kalshi are more likely to be seen as financial instruments.

Professional gamblers

Even professional gamblers in the UK are generally exempt from tax on their winnings — unlike in many other countries. The principle was established in the 1925 case Graham v Green and has been consistently upheld.

How the UK compares internationally

The UK's gambling exemption makes it potentially the most favorable jurisdiction for prediction market traders:

• UK: Potentially 0% if classified as gambling
• Switzerland: Potentially 0% if classified as private investment (but risky for active traders)
• Australia: Potentially 0% if classified as recreational gambling
• Ireland: Potentially 0% if classified as gambling, 33% CGT otherwise
• Germany: ~26.4% on all capital gains — no gambling exemption for financial instruments
• US: Variable (10–37% ordinary, or 0–20% long-term) — gambling method is usually the worst option

However, the UK exemption is a double-edged sword: if profits are tax-free, losses are also not deductible. For traders with a mix of wins and losses, CGT treatment might actually produce a lower tax bill in some years.

Self-Assessment considerations

If you determine your prediction market income is gambling (tax-free), you do not need to report it on your Self-Assessment tax return. However, if HMRC disagrees and reclassifies the income, penalties and back-taxes may apply. Keeping detailed records of your trading activity and reasoning for the gambling classification is essential.

Frequently asked questions

Can HMRC reclassify my prediction market profits as taxable?

Yes. If HMRC determines that your activity constitutes trading in financial instruments (rather than gambling), profits could be subject to income tax or CGT. This is more likely if you trade on CFTC-regulated platforms like Kalshi, which are clearly financial instruments rather than gambling venues.

What about spread betting — is it similar?

Yes. Spread betting profits are also tax-free in the UK under the gambling exemption. Prediction markets are conceptually similar to spread betting (binary outcome contracts), which strengthens the argument for gambling treatment.

Does the gambling exemption apply to non-UK residents trading in the UK?

The exemption applies to UK tax residents. Non-residents are generally not subject to UK CGT on financial assets anyway. The question only arises for UK tax residents trading on international prediction market platforms.