What is the difference between fixed odds and starting price in horse racing?

Fixed odds are the price you accept when placing your bet, locked in regardless of subsequent market movements. If you back a horse at 7/1 on Monday morning and it wins on Saturday, you receive 7/1 whether the starting price ends up at 4/1 or 12/1. Starting price is the official odds at the moment the race begins, determined by independent SP reporters who record on-course bookmaker prices.

How does Best Odds Guaranteed work in UK horse racing?

Best Odds Guaranteed pays you the better of your fixed odds or the starting price. Take a price at the time of betting, and if the SP is higher, your bet settles at SP instead. If the SP is lower, you keep your original fixed price. Settlement happens automatically.

What happens if a horse is withdrawn after I placed my fixed odds bet?

If your selected horse is withdrawn, your stake is returned and the bet is void. This applies to standard day-of-race fixed odds bets. If a different horse is withdrawn from the same race, your bet stands but may face a Rule 4 deduction based on how short the withdrawn horse was.