How we rank betting exchanges and prediction markets in the UK

What we rank

Our ranking of the best prediction markets in the UK compares betting exchanges licensed by the Gambling Commission. In Great Britain, a bet on whether something will happen, from a football match to an election, is gambling, and only operators with a Commission licence may offer it. An exchange needs a betting intermediary licence, which the Commission says is “also commonly known as a betting exchange”, and it must take bets at the web addresses on the Commission’s public register.

Nine companies held that licence on the register of October 22, 2026. We rank three, Smarkets, Betfair Exchange and Matchbook, and haven’t yet reviewed the others; Betdaq, whose operator still held a licence on that date, closed on October 21, 2026. Platforms without a British licence are never eligible, however well known: that includes Polymarket and Kalshi, which both keep UK users out. Our guide to whether prediction markets are legal in the UK explains why.

The six criteria

Each criterion gets a rating from 0 to 10; the overall score is the weighted average, rounded to one decimal, and the ranking follows it.

How commission and fees are scored

An exchange doesn’t build a margin into its odds; it charges commission on your net winnings in each market, so the commission is its price. We score the whole cost:

• The standard rate, and whether the exchange publishes it. Smarkets publishes 2% of net winnings per market; Betfair’s charges page gives 2% for its Basic package as an example; we couldn’t read Matchbook’s rates from outside the UK.
• Extra charges for very active or very profitable customers, such as Smarkets’ 1% Pro and 3% Select tiers, charged on every settled bet, and Betfair’s Expert Fee, which tops up the fees of accounts with more than £25,000 of gross profit over 52 active weeks to 20% or 40% of their gross profit.
• Payment and API fees, such as Smarkets’ £150 API setup fee and Betfair’s £499 live API key.

An exchange whose rates we couldn’t check scores conservatively. Our commission calculator shows what any rate costs on a bet, and how it compares with a bookmaker’s odds.

How we rate the other criteria

• Licensing & safety: a current exchange licence, held since 2014 by all three exchanges we rank, starts near the top. Fines and settlements on the Commission’s regulatory action register, which covers decisions since November 2023, cost points: Betfair’s licensee was part of a £2 million settlement in December 2025.
• Markets & features: sports and racing, politics and current affairs, in-play trading with published delays, trade out, bet builders, streaming, yes/no prediction markets, and API access and its price.
• Liquidity: on an exchange, every bet needs someone to take the other side, so more users mean better prices and more bets matched. We couldn’t get matched-volume figures that compare the exchanges, so we judge each one’s user base by its ratings on the UK App Store and Google Play.
• Deposits & withdrawals: published withdrawal times count most, then fees, minimums and the choice of methods. An exchange whose payment pages we couldn’t read scores conservatively.
• App & experience: ratings on the UK App Store and Google Play on the date checked, weighted by how many people rated them, plus support channels and hours.

How the score works

The overall score is calculated automatically from the six ratings and their weights. A lower-scoring exchange never sits above a higher-scoring one, and our site won’t publish if it does.

What we leave out

Bonuses and promotions. They’re legal in the UK, with wagering requirements capped at 10 times since January 19, 2026, but we compare the exchanges themselves, not their offers. Unlicensed platforms, including Polymarket and Kalshi. Spread-betting firms such as Spreadex, which is authorised by the Financial Conduct Authority and licensed by the Gambling Commission only for its fixed-odds betting; they aren’t exchanges, so we don’t score them here.

Where our facts come from

The Gambling Commission’s register of businesses and its regulatory action register, the Gambling Act 2005, each exchange’s commission and charges pages, help centre and developer documentation, and the UK App Store and Google Play, each dated on the page. Where an exchange’s site was blocked to us from outside the UK, as Betfair’s and Matchbook’s were, we used its app listings, developer pages or dated Internet Archive copies, and the review says so.

Independence

SafeBet.ai may be paid by exchanges whose links are marked as advertising, but an exchange can’t buy a place or a score. See our editorial policy, and tell us if something’s out of date.