A void bet is one that has been cancelled and refunded. The stake is returned to the bettor in full, and the bet is treated as if it never existed. Voids are not losses — they are cancelled transactions. Understanding when and why bets are voided is important for managing expectations and accumulator betting.
Common reasons for voiding include: event cancellation or postponement (a match called off due to weather), non-runners in horse racing (a horse withdrawn before the race), player did not participate (a named goalscorer market voided if the player was not in the starting lineup), and palpable errors (a bookmaker pricing an event incorrectly due to human or technical error — e.g. offering 10.0 on a near-certainty).
Accumulator impact is the most significant practical consequence of voids. In a six-fold accumulator, one void reduces the bet to a five-fold. The odds are recalculated — the voided leg's odds are effectively set to 1.0 (no multiplication). This can sometimes work in your favour if the voided selection was odds-on, as removing it does not dramatically hurt the overall combined odds.
Postponed matches vs abandoned matches are treated differently in some bookmakers. A postponed match (rescheduled for a later date) is usually voided. An abandoned match that has passed the bookmaker's "in progress" threshold (often 55+ minutes for football) may be settled on the result at the time of abandonment. Always check terms.
Example
You place a five-fold accumulator. Before one match kicks off, a key named player withdraws (for a player-specific market). That leg is voided. Your five-fold becomes a four-fold, odds recalculated. If the remaining four legs win, your accumulator pays out on the four-fold odds — as if the fifth leg never existed.