Combining liability or ‘combined liability’ may be a term you come across when matched betting and it is a good idea to learn what it is so that you understand why certain amounts are deducted from your betting exchange balance when you place your lay bets.

In this matched betting guide, we’ll be looking at what combined liability is and how you can use it to your advantage when matched betting.

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What is liability?

The liability is the amount you stand to lose on your lay bet should it not win. With back bets, which we place with a bookmaker, we simply enter the stake and that is how much we will lose if our bet doesn’t win. However, with lay bets, we are essentially acting as the bookmaker and have both a stake and a liability.

Lay Stake – The the amount you will win if your lay bet wins.

Liability – The amount you will lose if your lay bet loses.


If we placed a £10 lay bet on Chelsea at odds of 2/1 (3.0), our liability would be £20.

A good way to think of lay bets is that you are the bookmaker and the lay stake is the punters bet. So, if a punter wanted to place £10 on Chelsea to win, you would profit £10 if Chelsea didn’t win and pay out £20 if they did win which is the same outcome as with your lay bet.

Combined Liability

If we place more than one lay bet on an event where those bets are in related markets, we’re able to combine the liability of those bets.


Chelsea v Liverpool

  • We place a £10 lay bet on Chelsea at odds of 3.0
  • Liability = £20
  • We also place a£10 lay bet on Liverpool at odds of 2.0
  • Liability = £10

If you place these two bets, you may expect £30 to be deducted from your exchange account (£20 + £10). However, only one team can win the match and so it is not possible that both your lay bets can lose.

Possible outcomes:

  • Match ends in a draw: Both lay bets win – £20 profit
  • Chelsea win: Your Liverpool lay bet wins – £10 loss
  • Liverpool win: Your Chelsea lay bet wins – Break even

As you can see, the maximum we stand to lose is £10 and so only this amount is deducted from our exchange account rather than the full £30.

Order of placing your bets

In some circumstances, you may need more than the combined liability in your account to initially place your bets depending on what order you place those bets.

For example, if we placed our £10 lay bet on Chelsea first, our account would be deducted the liability amount of £20. Should we then place a £10 lay bet on Liverpool, £10 would actually be credited to our exchange account as we now have combined liability.

However, if we place our £10 lay bet on Liverpool first, only £10 is deducted from our account. If we were then to place our £10 lay bet on Chelsea, our balance would remain the same as the combined liability is the same as what has already been deducted.

Example 2

Now let’s take a look at an example of a horse race where we are laying multiple selections. Tools such as a horse racing matcher come in handy for finding good matches on horse races.

In the example below, we have placed lay bets on three horses in a six-horse race.

combined liability

Again, all three of our lay bets can’t lose as they’ll only lose if the horse wins and only one horse can win the race.

The total liability of the three lay bets is £131 but Betfair have only requested £78 which is the greatest liability of the three. However, our combined liability is actually less than that and so once all three bets have been successfully matched, we will receive money back. Initially, Betfair will require you to have funds in your account equal to or above the highest liability amount in case the other lay bets are not matched.

Let’s take a look at the possible outcomes and what the combined liability will be.

Horse 1 wins: We lose £21 and make £20 leaving us £1 down

Horse 2 wins: We lose £78 and make £15, leaving us £63 down

Horse 3 wins: We lose £32 and make £25, leaving us £7 down

Another horse wins: We make £30 profit

As you can see, the worst case scenario is if Horse 2 wins and we’re £63 down. Therefore, once all three bets have been matched, this is the amount that will be deducted from our exchange balance rather than the full liability of £131.

Benefits of Combined Liability

Combining liability allows you to free up more of your exchange funds which means you can participate in more offers.

Obviously, it is not advisable that you bet on multiple outcomes at the same bookmaker but should you have say, two £10 free bets with different bookmakers, placing them on opposite teams in the same match or different horses in the same race will mean that your exchange balance is not debited as much.

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