What Is Matched Betting? How It Works, the Maths and the Risks

Matched betting is a way of turning bookmaker promotions, usually free bets, into cash by placing two opposing bets on the same event. One bet backs an outcome with the bookmaker. The other lays the same outcome on a betting exchange, which means betting that it will not happen. Because the two bets cancel each other, the result of the match stops mattering. What is left over is the value of the free bet.

It is not a system for predicting football. It is closer to arbitrage: the profit comes from the promotion, not from being right about the sport. That is also why it only works while promotions last and while a bookmaker is willing to keep offering them to you.

A back bet is the ordinary bet everyone knows. You back Arsenal to win at odds of 3.0 with a bookmaker, stake £10, and collect £30 if they win. Bookmakers offer sign-up promotions along the lines of "bet £10, get £30 in free bets". Those free bets are the raw material.

A lay bet is only available on a betting exchange such as the Betfair Exchange, Smarkets or Matchbook. When you lay Arsenal, you are acting as the bookmaker for another customer: you win their stake if Arsenal fail to win, and you pay out at the agreed odds if Arsenal do win. The amount you could lose is called your liability, and the exchange holds it in your balance until the match settles. Exchanges charge commission on net winnings, typically between about 2% and 5% depending on the exchange and your account.

Suppose a bookmaker offers "bet £10, get a £10 free bet". The free bet is stake-not-returned, meaning if it wins you keep the winnings but not the £10 stake. Assume exchange commission of 2%.

You back Arsenal at 3.0 with £10 at the bookmaker, then lay Arsenal on the exchange at 3.1. The lay stake that balances the two sides is the back odds multiplied by the back stake, divided by the lay odds minus the commission: 3.0 × £10 ÷ (3.1 − 0.02) = £9.74. Your liability is £9.74 × (3.1 − 1) = £20.45.

The qualifying bet costs 45p whatever happens, and the £10 free bet is now in your account.

Free bets are worth most on longer odds, because the stake you do not get back is a smaller share of the return. You place the £10 free bet on a selection at 5.0 and lay it at 5.2. For a stake-not-returned free bet the lay stake is (back odds − 1) × stake ÷ (lay odds − commission): 4 × £10 ÷ 5.18 = £7.72. Liability: £7.72 × 4.2 = £32.43.

Across both steps you have turned a £10 promotion into £7.12 of cash, roughly 71% of its face value. That conversion rate, somewhere between 70% and 80% of a stake-not-returned free bet, is the number to remember. A free bet whose stake is returned is worth close to 95%.

Sign-up offers are the largest single promotions and they only come once per bookmaker. Someone working through the main licensed British bookmakers in 2026 can expect a few hundred pounds from welcome offers over a month or two, after which income depends on reload promotions: price boosts, acca insurance, "bet £20 get £5" style weekly offers and casino promotions, which carry different and usually worse maths.

Two things cap the income. First, every bet requires money up front: the exchange holds your liability, so a £32 liability needs £32 sitting in your exchange balance even though your eventual profit is £7.57. Second, bookmakers monitor accounts. An account that only ever bets to unlock promotions tends to be restricted to tiny stakes or excluded from promotions within weeks or months. The industry word for this is being "gubbed", and it is the normal end of a matched-betting career with any given bookmaker.

Yes. Placing a bet with a licensed bookmaker and a lay bet with a licensed exchange are both ordinary, legal transactions, and nothing in the Gambling Act 2005 or the Gambling Commission's licence conditions prohibits a customer from using promotions as advertised. Bookmakers write their own terms, and those terms can exclude customers from promotions or close accounts, so it is a contractual matter between you and the operator rather than a legal one.

Winnings are also tax-free for individuals in the UK. HM Revenue & Customs treats betting as something that does not constitute trading, even for people who do it systematically or make a living from it. There is more detail in our guide to tax on gambling winnings in the UK.

Only use operators on the Gambling Commission's public register. Promotions from unlicensed sites cannot be relied on and offer no dispute route.

No. The maths of a correctly placed matched bet is risk-free, but the process involves people, markets and terms. Treat it as low-risk with a known small loss per mistake.

No. The sport is irrelevant; you are only choosing events where the back and lay prices are close together.

Bets do not appear on credit files. Bookmakers may run soft identity and affordability checks, which do not affect your score.

Only where both a licensed bookmaker with promotions and a betting exchange are legal and available. Many countries have no exchange, which makes true matched betting impossible. Tax treatment also differs: several jurisdictions tax winnings.

Income drops to whatever reload promotions your remaining unrestricted accounts offer. Many people stop at that point; the hourly rate of chasing small weekly offers is low.

Related guides: how betting odds work, including the odds converter you will need for lay calculations, and each-way betting, which some promotions target. If gambling has stopped being a calculation and started being a problem, our responsible gambling page lists free support.

Sources: HM Revenue & Customs, Business Income Manual BIM22017, "Betting and gambling: the professional gambler" (official guidance); Gambling Commission public register of licensed operators (official register); and Betfair, "Betfair charges" (exchange commission terms). Promotion terms and exchange commission change frequently; check the live terms before placing either bet.