Are prediction markets legal in the UK? Polymarket, Kalshi and betting exchanges

The short answer

Great Britain treats a bet on whether something will happen as gambling, whatever the event, and gambling is legal with an operator licensed by the Gambling Commission. So you can legally bet on an election, a party leadership contest or a TV show, at a licensed bookmaker or betting exchange, if you’re 18 or over. What isn’t legal is offering those bets to people in Great Britain without a licence, or advertising such an offer.

That’s why the big international prediction markets aren’t available here: Polymarket and Kalshi hold no British licence, and both block UK users themselves.

Betting exchanges: Britain’s licensed prediction markets

A betting exchange brings bettors together and takes no side itself: you can back an outcome to happen or lay it, at prices set by other users, and the exchange takes a commission on your net winnings. The Commission licenses exchanges as betting intermediaries; its own licence page says a remote betting intermediary “is also commonly known as a betting exchange”. Nine companies held that licence on the register of October 22, 2026, among them the operators of Betfair, Smarkets and Matchbook.

Some exchanges now present their markets the prediction-market way, with yes-or-no questions priced as percentages. Smarkets calls its app “Smarkets: Prediction Markets”, and Matchbook launched Matchbook Predictions with ADI Predict Street by June 2026, at an address the register lists for Matchbook’s operator, Triplebet Limited, with markets from football to general elections. The register also shows a pending general betting licence for IG View Limited, with the trading name “IG prediction markets”. Compare the licensed exchanges in our exchange ranking.

Polymarket and Kalshi

• Polymarket’s list of geographic restrictions puts the United Kingdom among the places where users can close existing positions but can’t open new ones. See is Polymarket legal in the UK?
• Kalshi, a US exchange regulated by the Commodity Futures Trading Commission, lists the United Kingdom among the restricted jurisdictions from which its members may not trade.

Neither appears on the Gambling Commission’s register.

Event contracts as financial products

Some event contracts are sold as financial instruments rather than bets. In the UK, the Financial Conduct Authority has permanently banned firms from selling, marketing or distributing binary options to retail customers since April 2, 2019, and its definition is broad: products “that involve an investor ‘betting’ on whether an event will happen or not”, with a predetermined payout. Event contracts that fall under it can’t be offered to ordinary investors.

Inside information

Betting on politics is legal; cheating isn’t. Under section 42 of the Gambling Act, deception or interference in connection with gambling, or with the event bet on, is an offence carrying up to two years in prison. The Commission is prosecuting people accused of betting on the date of the July 2024 general election with inside knowledge: on September 10, 2026, two more defendants pleaded guilty to cheating, with sentencing set for October 23, 2026, and trials of ten others are scheduled for September 2027 and January 2028.

Tax

Winnings from bets, including on exchanges, aren’t taxed: HMRC’s position is that betting isn’t a trade for the bettor. See gambling taxes in the UK.