- What an accumulator bet means in UK betting
- Doubles, trebles and bigger accas explained
- Working out acca returns with decimal odds
- Why each extra selection makes an acca less likely to land
- Each-way accas and full cover bets
- Accumulator rules, ages and where to check them
- Help with gambling and keeping it fun
- Writing about football odds and betting markets
- Frequently asked questions
An accumulator bet, or acca, is a single bet that links several selections, and every one must win for you to get a return. In UK betting, two selections make a double, three a treble and four or more an accumulator. The odds multiply, so returns grow, but each added selection lowers the chance of winning.
Ask anyone in a UK pub about their weekend football bet and there's a good chance they'll mention an acca. Accumulators are hugely familiar on this side of the Atlantic, but the terminology around them, from doubles and trebles to Yankees and each-way multiples, can be baffling if you've never placed one.
This is a neutral explainer for adults, drawn from Wikipedia's glossary of bets offered by UK bookmakers, its articles on parlays and odds, the Gambling Commission and GambleAware. I'm not recommending any bet, and there are no tips here. If gambling's worrying you, free and confidential support is listed further down.
What an accumulator bet means in UK betting
Wikipedia's glossary of UK bets defines an accumulator as "a bet on four or more selections, all of which must win to gain a return". Accumulators are named by the number of selections, so you'll see fourfold, fivefold and so on. It's commonly shortened to acca.
In the US, the same bet is called a parlay, and Wikipedia also lists combo bet and multi as alternative names. If you've come across the American version, my guide on how a parlay works covers US terms such as pushes and same-game parlays.
Doubles, trebles and bigger accas explained
| Bet name | Number of selections | What has to happen |
|---|---|---|
| Double | 2 | Both selections must win to gain a return |
| Treble | 3 | All three selections must win |
| Fourfold accumulator | 4 | All four selections must win |
| Fivefold, sixfold and beyond | 5, 6 and up | Every selection must win |
Doubles and trebles work exactly like accumulators but have their own names in UK betting, which is why the glossary keeps the word accumulator for four or more selections.
Working out acca returns with decimal odds
Wikipedia's article on odds explains that decimal odds include the original stake, so the total return on a single winning bet is the stake multiplied by the decimal odds. It also notes that decimal odds equal fractional odds plus one, so 4/1 is the same as 5.0. Decimal odds suit multiple bets because the odds for the whole bet are simply the product of each selection's odds.
Worked example (illustrative odds only): picture a fourfold on four football matches with decimal odds of 1.50, 2.00, 2.00 and 2.50. Multiply them together and you get 1.50 x 2.00 x 2.00 x 2.50 = 15.00. A stake of 10 units would return 150 units in total if all four results came in. If any single result went the wrong way, the whole bet would lose.
Football shows how fine the margins are. One late goal, a red card or a goal ruled out after a review of the offside rule can change a single result, and with it the entire acca.
Why each extra selection makes an acca less likely to land
The growing odds on an accumulator reflect how unlikely it'd be for every result to go your way. Each selection you add is another result that has to be right, so the chance of the whole bet winning falls with every addition, even if each selection looks likely on its own.
There's also the bookmaker's margin to think about. Wikipedia explains that bookmakers often settle multiple bets at less than the true odds and describes the house edge as increasing in parlays, which is the same thing as an acca. Its article on full cover bets makes a similar point: the bookmaker's overround compounds when bets are combined.
Each-way accas and full cover bets
Two related bet types often appear alongside accumulators, especially in horse racing:
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- Each-way multiples. An each-way bet is a win bet and a place bet of equal size. The glossary says each-way multiple bets are settled on a win-to-win and place-to-place basis, and that the place part is often based on a fixed proportion of the win odds, which varies with the bookmaker's terms.
- Trixie. Three selections making four bets: three doubles and a treble.
- Yankee. Four selections making 11 bets: six doubles, four trebles and a fourfold accumulator.
- Lucky 15. Four selections making 15 bets: four singles, six doubles, four trebles and a fourfold accumulator.
Full cover bets mean a return is possible without every selection winning, but each line is a separate bet, so the total amount staked is several times the unit stake. A straight acca, by contrast, is one bet that needs everything to win.
Accumulator rules, ages and where to check them
- Minimum age: the Gambling Commission says that in most cases the minimum legal age for gambling in Great Britain is 18, covering betting shops and online gambling. Age limits differ in other countries and, in the US, from state to state.
- Postponed matches and non-runners: each bookmaker's terms set out what happens to a selection that doesn't take place, so read them before you place a bet.
- Bonuses and offers: any extras come with their own terms, which can change how a bet's settled.
Help with gambling and keeping it fun
If betting stops feeling like entertainment, or you're worried about someone close to you, help is free and confidential. GambleAware offers support in Great Britain 24/7 by phone or online chat, and the National Gambling Helpline, run by GamCare, is on 0808 8020 133, 24 hours a day.
- Treat any stake as gone the moment you place it.
- Never chase losses with a bigger or longer acca.
- Take a break if it's affecting your sleep, mood, relationships or work.
- Talk to a helpline adviser, your GP or a counsellor if you're struggling.
Writing about football odds and betting markets
Plain explanations of how bets are settled help readers understand exactly what they're agreeing to. If you write about football markets, odds or responsible gambling, there are publications that welcome that knowledge.
If you cover football markets and odds, there's a list of sports betting sites open to new writers here.
Frequently asked questions
What does acca stand for?
Acca is short for accumulator, a single bet that links several selections together. Every selection must win for the bet to return anything.
Is a double an accumulator?
It works the same way, but UK betting gives it its own name. The glossary of UK bets uses double for two selections, treble for three and accumulator for four or more.
Is an accumulator the same as a parlay?
Yes. Parlay is the usual US term, and Wikipedia lists accumulator, acca, combo bet and multi as other names for the same type of bet.
What is a Lucky 15?
It's a full cover bet on four selections made up of 15 bets: four singles, six doubles, four trebles and a fourfold accumulator.
Where can I get help if gambling is a problem?
In Great Britain, the National Gambling Helpline run by GamCare is free on 0808 8020 133, 24 hours a day. GambleAware also offers free, confidential support by phone and online chat.
