Most matched betting guides start at "lay at 3.1, mind the liability, it's SNR so go higher". That's a foreign language until someone translates it. The maths underneath is simple. The words are what put people off. So this page assumes you know nothing about betting at all. By the end you'll understand every number in a matched bet and why it works. I used to teach this in mastermind sessions that sold for over £1,000 a seat. This page is the same material, free.
The idea in 30 seconds
Bookmakers give away free bets to win new customers: "bet £10, get a £10 free bet". Most people stick the free bet on a favourite and hope. Sometimes it wins, often it doesn't, and either way the bookmaker has got a new customer.
A matched bettor does something else. For every bet at the bookmaker, they place an opposite bet at a betting exchange, a website where people bet against each other instead of against a bookmaker. One of the two bets always wins and the other always loses. Set the stakes right and the result is the same whatever happens.
On your own money that "same result" is a loss of a few pence. On the bookmaker's free bet it's a profit, because the free bet costs you nothing if it loses. Repeat that across dozens of bookmakers and offers and it adds up.
Bookmaker
You BACK it
"Arsenal will win"
Exchange
You LAY it
"Arsenal won't win"
The eight words you need
- Back
- An ordinary bet: you're saying something will happen. "Back Arsenal" means bet on Arsenal to win. This is what you do at a bookmaker.
- Lay
- The opposite: you're saying something won't happen. If you lay Arsenal, you win if Arsenal draw or lose. Laying makes you the bookmaker for that one bet, and someone else on the exchange takes the other side.
- Betting exchange
- A marketplace where punters bet against each other: Betfair Exchange, Smarkets, Matchbook. It's the only normal place you can lay a bet, so you need one account at an exchange. It makes money by taking a small commission on winnings.
- Decimal odds
- The price, shown as one number that includes your stake. At odds of 3.0, a £10 bet returns £30 if it wins: your £10 back plus £20 profit. Odds of 2.0 double your money. Fractional odds convert by adding 1: 2/1 is 3.0, evens is 2.0, 4/1 is 5.0. Matched betting runs on decimal odds, so switch your bookmaker accounts to decimal in the settings.
- Liability
- When you lay, you're the one paying out if the result happens, so you need that money in your exchange account first. Liability = lay stake × (lay odds − 1). Lay £9.74 at 3.1 and your liability is £9.74 × 2.1 = £20.45. If you lose the lay, that's what leaves your account. If you win it, you collect the £9.74 stake.
- Commission
- The exchange's cut, taken only from what you win there, typically somewhere between 2% and 5% depending on the exchange. The calculators build it into the lay stake, so you don't have to think about it, but it's why the numbers below aren't perfectly round.
- Qualifying bet
- The bet with your own money that unlocks the offer, e.g. "bet £10". You back it and lay it straight away, so whatever happens you lose a few pence. That small loss is the price of the free bet.
- Free bet: SNR vs SR
- Almost every UK free bet is SNR, stake not returned: a £10 free bet at 5.0 pays £40 if it wins, not £50, because you don't get the "stake" back. You never had it. That's why you lay free bets at higher odds (around 4.0–8.0): the missing stake is a smaller share of a bigger win. SR, stake returned, pays the full £50. It's rare and worth more. Expect to keep about 70–80% of an SNR free bet's face value. I aimed for about 80% on reloads.
A full worked example: one sign-up offer, start to finish
The offer: "Bet £10 at odds of 2.0 or more, get a £10 free bet." The exchange charges 2% commission. Two bets, and you can follow every penny.
Bet A: the qualifying bet (your £10)
Back £10 on Arsenal at 3.0 at the bookie. Lay £9.74 on Arsenal at 3.1 at the exchange (2% commission). Liability: £20.45.
| If… | Bookie | Exchange | You end up |
|---|---|---|---|
| Arsenal win | +£20.00 | −£20.45 | −£0.45 |
| Arsenal don't win | −£10.00 | +£9.55 (£9.74 less 2%) | −£0.45 |
That 45p is the qualifying loss: what it costs you to unlock the free bet. Same either way.
Bet B: the £10 free bet (the bookie's money)
Back the £10 free bet at 5.0. Lay £7.72 at 5.2 at the exchange. Liability: £32.43.
| If… | Bookie | Exchange | You end up |
|---|---|---|---|
| Your pick wins | +£40.00 (stake not returned) | −£32.43 | +£7.57 |
| Your pick loses | £0 (it was free) | +£7.57 (£7.72 less 2%) | +£7.57 |
Offer total: £7.57 − £0.45 = £7.12 profit, decided before a ball is kicked.
Notice what you never did: pick a winner. Arsenal could have won 5–0 or lost 5–0 and the answer would be the same £7.12. That's the whole point. You don't need to know anything about football or horses, and knowing a lot doesn't help.
Two practical notes. First, place the two bets back to back, seconds apart, and never leave one side unmatched. For the qualifying bet, most people place the bookmaker bet first, because bookmaker prices move and bets sometimes get rejected. For a free bet, laying first has its own advantage (the free bet calculator explains why). And the qualifying bet had to be at odds of 2.0 or more, which is why 3.0 was fine. Always check the minimum odds in the terms.
Want to check it yourself? Put the same numbers into the matched betting calculator (qualifying bet) and the free bet calculator (SNR). You'll get £9.74, £20.45, £7.72, £32.43 and £7.57, the same as above.
What you need to start
- An exchange account. Betfair Exchange, Smarkets or Matchbook. Commission and liquidity (how much money is available at each price) differ, and plenty of people end up with more than one.
- Bookmaker accounts. One per offer. Each bookmaker gives you one sign-up offer, and the UK has dozens of bookmakers. Use your real details. It's your money and you'll need ID checks to withdraw.
- A float. This is the cash sitting across your bookmaker and exchange accounts. The £10 example needs £10 at the bookie and £20.45 liability at the exchange, then £32.43 liability for the free bet. Money is tied up until bets settle, so a few hundred pounds lets you run several offers at once. The float also matters more later on, as you'll see below.
- A calculator and an odds-matching tool. The calculators on this site are free. Finding a bookmaker price and an exchange price close enough together by hand is the slow bit, and that's what paid tools like OddsMonkey's oddsmatcher do.
- A simple spreadsheet. Date, offer, qualifying loss, free bet profit, running total. Your bank statement won't tell you whether you're up, because the money moves between too many accounts.
- A debit card, ideally on a bank account you keep just for this. Many offers exclude e-wallet deposits such as PayPal or Skrill. That's in the terms.
How long it takes and what it actually pays
Your first offer will be slow. Reading the terms, finding a match, double-checking the lay stake, double-checking it again. That's fine. Once the routine is second nature, a straightforward sign-up offer takes a fraction of that.
The money is easy to estimate because every offer is just arithmetic. A £10 free bet is worth roughly £7 after the qualifying loss, a £20 free bet roughly £14, a £30 one roughly £21. Add up the sign-up offers available to you and you have a fair idea of the first stretch. For what it's worth, I made about £1,000 in my first four weeks in 2017, on sign-up offers at Betfred, Coral, Ladbrokes, Bet365 and others.
The honest bit: sign-up offers run out. Each bookmaker gives you one. After that the money comes from reload offers for existing customers, like free bets for placing a bet on the weekend's football, or acca insurance (a free bet back if one leg of your accumulator lets you down). They're smaller and more fiddly. Over time, some accounts get restricted (see gubbing, below). Once I was past the sign-ups I averaged four figures a month, but that included the more advanced methods I describe further down, not just plain matched betting.
The mistakes that cost money
Matched betting removes the luck. It doesn't remove human error, and an unmatched bet is a real bet with real risk. These are the common ones:
- Laying the wrong thing. Backing Arsenal and laying Chelsea, or laying the wrong market (match odds vs. draw no bet). Read the selection and market on both sites before you click.
- Backing when you meant to lay. On the exchange, "Back" is blue and "Lay" is pink. Click the pink one.
- Not having the liability. Exchanges only take a lay if your balance covers the liability. Deposit first, or your bookmaker bet sits there unmatched.
- Getting the odds or stake slightly wrong. Typing the stake, missing a price change, or using a stake from a different calculation. Re-check that the two outcomes in the calculator match before you place anything.
- Missing a term. Minimum odds, the qualifying market, "first bet only", "free bet must be used within 7 days", excluded payment methods. One missed line can void the free bet after you've paid the qualifying loss.
- Laying a free bet at short odds. A £10 SNR free bet laid at 2.0/2.04 keeps about £4.85. At 5.0/5.2 it keeps £7.57. Same free bet, very different result.
- Jumping to the advanced stuff too early. Each-way value betting and casino offers swing. Doing them before you've built a float is how people go broke on a method that's profitable on average.
Is it legal? Is it taxed?
Legal: yes. You're placing ordinary bets with UK-licensed bookmakers and an exchange, inside their published terms. Nobody is being tricked. The bookmaker has priced the free bet as a marketing cost, and you're using it more carefully than they'd like. They're allowed to stop you (that's gubbing), but they can't treat it as a crime, because it isn't one.
Tax: in the UK, gambling winnings aren't subject to income tax, and that includes matched betting profit. The bookmakers pay their own betting duty instead. It's one reason the UK is the best place on the planet to do this. The other is that it has one of the most competitive bookmaker markets anywhere, which means a steady stream of offers. This is general information, not tax advice. If your situation is unusual, ask an accountant.
One practical catch: mortgages. Lenders read bank statements, and dozens of bookmaker and exchange transactions can look like a gambling problem even when you're up. If you're applying soon, wind down first and be ready to explain.
Gubbing: when the bookies stop playing
"Gubbing" is when a bookmaker restricts your account. Usually you stop getting promotions, or your maximum stake drops to pennies. It happens because bookmakers can spot matched bettors from their patterns: only betting on offers, stakes to the penny, always on markets with a lay price. It's legal, there's no appeal, and it's part of the game. Your sign-up offer will usually be honoured, but the reloads that come after won't last forever.
I was gubbed by nearly every bookie I used, Bet365 included. One account was closed after I won £4k in a day. Gubbing doesn't undo anything. Every offer you complete before an account is restricted is profit already banked. What it does mean is that no single bookmaker will keep paying you forever, so the money comes from working through many of them.
After the basics: from float to +EV
Everything above has a known outcome. It's the foundation, and for a lot of people it's all they'll ever need. But it isn't where the biggest numbers came from for me, and I'm not going to pretend it was.
Once matched betting had built me a float, I moved into plays that make money on average but swing a lot from one bet to the next. That's what "positive expected value", or +EV, means:
- Each-way no-lay. An each-way bet is two bets on a horse: one to win, one to place (finish in the top few). When a bookie's each-way terms are generous compared with the exchange prices, the bet is worth more than it costs on average. You don't lay it. You back it and let the maths play out over hundreds of bets.
- Lucky 15s. Four horses, 15 bets: four singles, six doubles, four trebles and a four-horse accumulator. Each-way, that's 30 bets. Built from each-way no-lay selections, it compounds the edge. It's been called a +EV lottery ticket. I made almost £5k on one.
- Casino offers. Slots pay back about 95% of stakes on average over time (RTP, "return to player"). When a bonus or free spins add more than that missing 5%, the average result is profit. Any single session can go either way.
- Bet365's 2-up (as it ran then): your football bet paid out as a winner if your team went two goals ahead. Back at Bet365, lay at the exchange, and when a team went two up and then failed to win, both sides paid.
These are not matched betting in the known-outcome sense. You can lose money on any single bet, and you can lose for weeks. The float is what lets you ride that out without stopping, which is why the order matters: matched betting first, float second, +EV third. I'll cover each one properly on its own page.
Where OddsMonkey fits
You can do everything on this page with a free calculator and some patience. Where a subscription earns its money is the slow parts:
- Oddsmatcher: scans bookmaker prices against the exchanges and ranks the closest matches, so you're not hunting through markets by hand.
- Offer guides: step-by-step walkthroughs of each sign-up and reload offer, including the terms that catch people out.
- Tools for the advanced stuff: I used OddsMonkey's tools, alongside Bookie Bashing's, for each-way value betting.
OddsMonkey is where I started in 2017, after an article sent me to MoneySavingExpert and MoneySavingExpert sent me there. I'm an affiliate, which I'll always flag, and you can read my review before you decide.