Rule 4 deductions in UK horse racing explained
12 November 2026
When a horse is withdrawn after you have placed your bet and before the race starts, the odds on the remaining runners no longer reflect the field you backed into. Rule 4 is the mechanism that corrects for this. It trims the winnings on bets that were struck before the withdrawal, and the size of the trim depends mainly on how short the missing horse was in the betting. A big favourite coming out costs backers of the others a great deal. A rank outsider coming out costs them nothing.
What Rule 4 is and why deductions happen
The rule is set out in the Tattersalls Committee's rules on betting, a document dated 17 May 2010. It covers the case where a horse is withdrawn after a bet has been struck and before the race starts. In that situation, winnings on the remaining runners are reduced according to a published scale.
The reasoning is straightforward. Suppose you back a horse at 6/1 in a field where the 1/2 favourite is a strong certainty to be involved in the finish. The price you took already allowed for that favourite being in the race. If the favourite is then taken out, your horse's chance of winning improves, yet you are locked into odds that were set when the favourite was still running. Without a correction, the bookmaker would be paying out at prices that no longer matched the true risk.
Rule 4 therefore removes part of the return to compensate. The more likely the withdrawn horse was to win, the larger the deduction. That is why the scale is built around the non-runner's price at the time it came out, not around the horse you backed. Sky Bet's help pages say as much: the size of the deduction depends on the price of the non-runner at the time of withdrawal.
One point catches out plenty of punters. The deduction is not taken from your stake. Sky Bet explains that Rule 4 deductions come off each £1 of winnings. Your stake is still returned in full on a winning bet, and only the profit is reduced.
The Tattersalls deduction scale
The scale is a sliding one, with deductions growing larger as the withdrawn horse's price gets shorter. At the top end, a withdrawn horse priced at 1/9 or shorter attracts a deduction of 90p in the £1. Coral's help pages list the same scale, running from 90p for a horse at 1/9 or shorter down to no deduction for a horse over 14/1.
Further down the price range, a withdrawn horse priced between 10/1 and 14/1 carries a deduction of just 5p in the £1. Anything over 14/1 carries no deduction at all. The bands between those points step down gradually from the heavy deductions at short prices to the light ones at long prices, and the full table sits in the Tattersalls document that bookmakers work from.
In practice the extremes tell you most of what you need to know. A near-certainty being withdrawn will wipe out the bulk of your profit on any bet placed earlier. A 20/1 shot being withdrawn will not touch your returns. Most real-world withdrawals fall somewhere in the middle, where the deduction is noticeable without being devastating.
The reduction also has a ceiling. Under Tattersalls Rule 4, if two or more horses are withdrawn, the total reduction cannot exceed 90p in the pound. That matters in a big handicap where several horses come out in the hours before the off. The individual deductions are added together, but the combined figure stops at 90p, so you always keep at least 10p in each £1 of winnings.
The price used is the non-runner's price at the time of withdrawal, not the price it was when you placed your bet. If a horse drifted from 3/1 to 8/1 before it was pulled out, the withdrawal price is what counts. This matters when you look at the market before backing something. The depth of a deduction can only be known after the event, so the scale is best treated as a risk to be aware of, not a number you can fix in advance.
When Rule 4 does not apply
Not every bet is exposed to a deduction. The Tattersalls rule sets out clear exemptions, and knowing them can shape when and how you bet.
The most significant is ante-post betting. Tattersalls Rule 4 says ante-post bets are exempt from Rule 4 deductions. These are bets placed well ahead of the day, such as on a Grand National runner months before the race. The logic is that an ante-post punter accepts from the start that a horse may not run, and the bet is settled on that basis without any deduction applied for other horses coming out.
The second exemption concerns Starting Price bets. Tattersalls Rule 4 says bets placed at Starting Price are not affected if enough time exists for a new market to be formed after a withdrawal. The SP is set by the market at the off, so if the field has had time to reshape itself after a horse is pulled out, the final price already reflects the smaller field. A deduction on top would be a double correction. If a horse is withdrawn so late that no new market can form, the position is different, and the deduction can apply.
The practical consequence is that timing matters. A bet at a price taken in the morning and a bet at SP on the same race can be treated differently by the same withdrawal. Backers who want to avoid deductions sometimes choose SP for that reason, but it comes at the price of not knowing what odds they will get.
The exemptions also turn on how and when the bet was struck, not on which horse you backed. Reading the terms on your slip, and the bookmaker's help pages on horse racing rules, is the quickest way to see which category your bet falls into.
How bookmakers apply Rule 4 in practice
Operators publish their own help pages that follow the Tattersalls framework. The details below draw on Sky Bet's explanation and Coral's published scale.
- Deductions come from winnings, not stakes: Sky Bet states that the deduction is taken from each £1 in winnings, so a winning bet still returns your stake.
- The non-runner's price sets the deduction: Sky Bet says the size depends on the price of the horse at the time of its withdrawal.
- The scale starts at 90p: Coral lists 90p in the £1 for a withdrawn horse at 1/9 or shorter.
- Long-priced horses cost little or nothing: 5p in the £1 applies between 10/1 and 14/1, and nothing applies over 14/1.
- Multiple withdrawals are capped: under Tattersalls Rule 4, the combined reduction cannot go above 90p in the pound.
To see the arithmetic, take an illustrative £10 win bet at 5/1 that wins. Without a deduction the profit is £50 and the return is £60. If a horse priced between 10/1 and 14/1 had been withdrawn after the bet, the deduction would be 5p per £1 of winnings, or £2.50 on £50. The profit becomes £47.50 and the return £57.50. If instead a horse at 1/9 or shorter had been pulled out, the 90p deduction would reduce the £50 profit to £5, and the return would be £15.
Where the bookmaker shows the deduction on the bet's settlement, check it against the scale. Mistakes are not common, but the scale is simple enough for you to confirm the figure yourself using the withdrawn horse's price.
Each-way betting and settlement effects
Each-way bets can feel more complicated because they are two bets in one: a win part and a place part. Rule 4 works on the winnings from a bet, so any profit element in the return is open to reduction when a horse has been withdrawn after you backed yours. The stake element is not touched, in line with the way Sky Bet describes deductions being taken from winnings and not from the stake.
The practical point is that you may see a deduction applied to more than one part of an each-way return. A winning horse can bring profit from both the win and the place portions, and the deduction applies to the winnings in each. If your horse only places, there is still profit from the place part, and a deduction can still reduce it. The principle is the same across all of them: the scale is set by the withdrawn horse's price, and the 90p cap applies when several runners come out.
Where several horses are withdrawn, the cap protects you from the full total being deducted. Even if the individual deductions would add up to more than 90p, no more than 90p in the pound can be taken. An each-way bet on a race with a heavy run of non-runners will therefore still leave something in the winnings.
For anyone placing bets on big-field races with a history of late withdrawals, the sensible habit is to check the settled bet slip and not just the headline return. Look for the Rule 4 line, compare it with the withdrawn horse's price at the time it came out, and make sure the figure sits on the scale. If a bet was placed ante-post, or at SP with time for a new market, there should be no deduction at all.