If a race gets postponed to another day but the final declarations are unchanged, your bets will usually still be valid. That said, single bets on horse racing will be void, and accumulator selections will be treated as non-runners in certain cases. This includes when a race is abandoned, declared void, or if race conditions change after bets are placed. It also applies if the venue or surface changes, such as switching from turf to dirt or all-weather tracks.