Matched betting is a way of turning bookmaker free bet offers into a fairly predictable sum of money. You back a selection with a bookmaker, lay the same selection on a betting exchange, and size the lay so that the result of the event barely matters. Any profit comes from the free bet, not from predicting anything.
It is popular in the UK, where sign-up and reload offers are common and betting exchanges are well established. It is also more fiddly, and less risk-free, than it is often made to sound. This guide covers how back and lay bets fit together, the lay stake formulas for qualifying bets and free bets with exchange commission included, what goes wrong in practice, and why bookmakers restrict accounts that only take offers. We do not name or recommend any bookmaker, exchange or matched betting service, and the offer figures below are illustrations rather than real promotions.
Backing, laying and liability
An ordinary bet with a bookmaker is a back bet: you are betting that something will happen. A betting exchange also lets you lay, which means betting that it will not happen. When you lay, you take the bookmaker's role for another exchange customer who wants to back the same outcome.
The number that matters on a lay bet is the liability, the amount you pay out if the selection wins. It is the lay stake × (lay odds - 1). Lay £10 at 4.00 (3/1) and your liability is £10 × 3.00 = £30. If the selection loses, you win the £10 lay stake. If it wins, you lose £30. The exchange holds the liability from your balance as soon as the bet is matched, so you need that money in the account, not just the stake.
Exchanges make their money by charging commission on your net winnings in a market. Losing bets are not charged. Rates differ between exchanges and can differ between accounts, so use the rate shown on your own account. The examples here use 5%, which turns the £10 lay win above into £9.50.
The back price at the bookmaker and the lay price at the exchange for the same outcome are usually close but rarely identical. The lay price tends to be a little higher, and that small gap plus commission is why setting up a matched bet normally costs a few pence.
The qualifying bet
Most offers ask for a qualifying bet first: a bet with your own money, often at minimum odds set in the terms, after which the free bet is credited. The aim with the qualifying bet is to lose as little as possible.
For a normal cash bet, the lay stake that balances both outcomes is:
Lay stake = (back stake × back odds) ÷ (lay odds - commission)
Say the qualifying bet is £10 at 2/1 (3.00) and the exchange lay price for the same selection is 3.10. With 5% commission, the lay stake is (£10 × 3.00) ÷ (3.10 - 0.05) = £30 ÷ 3.05 = £9.84. Your liability is £9.84 × 2.10 = £20.66.
- If the selection wins, the bookmaker pays £20 profit and you lose the £20.66 liability on the exchange. Net result: -£0.66.
- If the selection loses, you lose the £10 bookmaker stake and win £9.84 on the exchange, which is £9.35 after commission. Net result: -£0.65.
That 65p or 66p is the qualifying loss. Part of it comes from the gap between 3.00 and 3.10 and part from commission. With no commission the same pair of bets would lose about 32p either way.
A common beginner mistake is to lay the same amount as the back stake. Laying £10 at 3.10 here gives -£1.00 if the selection wins and -£0.50 if it loses. The bet is no longer balanced, and those errors pile up over a run of offers.
Free bets where the stake is not returned
Most free bets are stake not returned (SNR). If the free bet wins, you receive the winnings but not the free bet stake itself, so a £10 free bet at 6.00 (5/1) pays £50, not £60. Because the stake never comes back, the lay formula uses the back odds minus one:
Lay stake = (free bet × (back odds - 1)) ÷ (lay odds - commission)
Using a £10 SNR free bet at 6.00 with a lay price of 6.20 and 5% commission, the lay stake is (£10 × 5.00) ÷ (6.20 - 0.05) = £50 ÷ 6.15 = £8.13, and the liability is £8.13 × 5.20 = £42.28.
- If the selection wins, the bookmaker pays £50 and you lose £42.28 on the exchange. Net result: +£7.72.
- If the selection loses, the free bet costs nothing and you win £8.13 on the exchange, £7.72 after commission. Net result: +£7.72.
The £10 free bet has turned into £7.72, about 77% of its face value. Take off the 65p or 66p from the qualifying bet and the whole illustrative offer is worth a little over £7.
Odds matter more here than anywhere else in matched betting. The same free bet at 2.00 with a lay price of 2.04 needs a lay stake of only £5.03 and keeps about £4.77, less than half its face value. At 4.00 with a lay price of 4.10 it keeps about £7.03. Higher odds keep more of an SNR free bet because the lost stake is a smaller share of what the bet pays. The trade-off is a bigger liability, which needs a larger exchange balance, and you need enough money waiting at the lay price for your whole lay to be matched.
Free bets where the stake is returned
Less often, a free bet is stake returned (SR), meaning a winning free bet pays the stake back as well. The lay stake then uses the full back odds, exactly like the qualifying bet formula. A £10 SR free bet at 6.00 with a lay price of 6.20 needs (£10 × 6.00) ÷ 6.15 = £9.76 laid, with a liability of £9.76 × 5.20 = £50.75. If the selection wins you collect £60 from the bookmaker and lose £50.75 on the exchange, a profit of £9.25. If it loses you win £9.76 on the exchange, £9.27 after commission. Because nothing is lost from the stake, an SR free bet keeps most of its value even at short odds, and there is less reason to chase bigger prices.
Read the offer terms to see which type you have. Using the SNR formula on an SR free bet, or the other way round, leaves the two outcomes unbalanced and costs money on one side.
Where matched betting goes wrong
The maths above works whichever way the event goes. Execution is where money gets lost, and the same mistakes come up again and again:
- Laying the wrong selection or market, such as backing a team in the 90-minute match result and laying them in a 'to qualify' market that includes extra time.
- Prices moving between the back bet and the lay bet. If the lay price changes, recalculate the stake with the price you can actually get.
- A lay bet left partly unmatched when the event starts, which leaves part of your back bet uncovered.
- Different settlement rules. A tennis retirement, an abandoned match or a dead heat can be settled one way by the bookmaker and another way by the exchange.
- Missing a condition in the offer terms: minimum odds, eligible markets, excluded payment methods, the deadline for using the free bet, or a free bet credited only once the qualifying bet settles.
- Not keeping enough balance on the exchange to cover the liability, especially on SNR free bets at higher odds.
The fix for most of these is slow, careful habits: one offer at a time, a written record of every back and lay, and a check that the expected result of each pair matches what settles.
Account restrictions and gubbing
Bookmakers give free bets to attract customers who will keep betting, not to hand money out. Their terms usually let them withdraw promotions from an account, limit stakes or close the account altogether, and they watch for patterns that suggest someone is only taking offers. In UK matched betting circles, an account that has been cut off from promotions is called gubbed.
Expect it to happen. Restriction is a normal outcome of matched betting, not a sign you did something wrong, and once a bookmaker stops sending you offers, that account is finished for matched betting purposes. It also means the total anyone can make is limited by the number of offers available to them, and those offers run out. Treat confident monthly income claims for matched betting with suspicion, including any extrapolation from the £7 example above: real offers vary, terms change and accounts get restricted.
Bookmakers may also carry out identity and affordability checks or ask where your money comes from, particularly when deposits and withdrawals are frequent. Keep your details accurate and only use accounts in your own name. Opening accounts in someone else's name, or more than one account per person, breaks bookmaker terms and can lead to winnings being withheld.
Tax, the law and gambling harm
Matched betting is a way of using ordinary bets, not a separate product, so the same rules apply as for any betting. You must be 18 or over, use operators licensed where you live, and follow their terms. Gambling laws differ from country to country, and most of the offers and exchanges that matched betting relies on are aimed at UK customers.
We do not give tax advice. How betting profits are treated depends on where you live and on your personal circumstances, and rules can change. Check your own situation using official guidance from your tax authority, which in the UK is HMRC, or ask a qualified adviser.
Matched betting also means spending a lot of time in bookmaker accounts and on betting apps. For some people that is harmless. For anyone who has had problems with gambling, it is a poor fit, because the offers are designed to keep you betting and the step from a matched bet to an unmatched one is small. Our responsible gambling page lists support services and tools such as deposit limits and self-exclusion.
Before you place a matched bet
Use the same routine every time so a mistake shows up before it costs money:
- Read the offer terms: qualifying stake, minimum odds, eligible markets, whether the free bet is SNR or SR, and when it expires.
- Find a selection where the bookmaker's back price and the exchange lay price are close, and check there is enough money available at the lay price.
- Calculate the lay stake with the correct formula and the commission rate on your own exchange account.
- Place the back bet, then the lay straight away, and confirm the lay is fully matched.
- Check both bets are on the same event, market and selection.
- Write down the expected result of the pair and compare it with what settles.
When the free bet arrives, recalculate with live prices; with the illustrative £10 SNR free bet at 6.00 and a lay at 6.20, a lay of £8.13 keeps £7.72 whichever way the event goes. The same lay and liability logic is used to hedge ordinary bets, which our guide to hedging and cash out covers.
Frequently asked questions
Is matched betting legal in the UK?
Matched betting uses ordinary bets with licensed bookmakers and exchanges, and it is widely practised in the UK. It does not exempt you from anything, though: bookmakers set their own terms and can withdraw offers, limit stakes or close accounts. If you live elsewhere, check your local gambling laws.
Is matched betting risk-free?
No. The maths balances both outcomes when everything is done correctly, but wrong stakes, unmatched lay bets, price changes and different settlement rules can all lose money. Bookmakers can also restrict your account at any time.
What does SNR mean on a free bet?
Stake not returned. If an SNR free bet wins, you receive the winnings only, so a £10 free bet at 6.00 pays £50. That is why the lay stake uses the back odds minus one and why SNR free bets keep more value at higher odds.
How does exchange commission change the lay stake?
Commission reduces what you win on the exchange, so the formula subtracts it from the lay odds: lay stake = back stake × back odds ÷ (lay odds - commission). With 5% commission and a lay price of 3.10, you divide by 3.05 instead of 3.10.
Do I have to pay tax on matched betting profits?
We do not give tax advice. Tax treatment depends on where you live and on your circumstances, so check official guidance from your tax authority, such as HMRC in the UK, or speak to a qualified adviser.
Why do bookmakers restrict matched bettors?
Free bets are a marketing cost meant to win customers who keep betting. Accounts that only take offers and lay everything off do not fit that, so bookmakers often withdraw promotions or limit those accounts under their terms.