If a non-runner is declared, it means that a selection will not be participating in the event.
The settlement process will depend on the type of bet that you placed.
Singles
If your selection is a non-runner your bet is made void, and your stake is returned.
Multiples
For bets such as Accumulators, if a selection is a non-runner, that selection is marked as void. However, your bet still stands and is settled on the remaining selections within the multiple.
For example, in a Treble, if one selection is a non-runner, the bet becomes a Double.
Important Tip
AntePost bets are All in, run or not, so should your selection withdraw, your bet will lose, unless otherwise stated.
Rule 4
If another participant other than your selection withdraws from an event, your bet may be subject to a Rule 4 deduction.
The Rule 4 deduction is an Industry standard where a deduction is applied for every 1.00 of your winnings. When odds are offered on an event, they are based on all participants taking part. When a participant withdraws from an event a Rule 4 deduction is applied to all bets placed before this point, to reflect the reduced number of participants running.
You can see any Rule 4 deductions and the time that it was applied to a market within an Event coupon.
You can find more details regarding Rule 4 deductions as well as the deduction table here.