Https://community.smartsheet.com/profile/204927/SIA_24hr [SIA-24hr-Cancellation] Does Singapore Airlines have a 24 hour cancellation policy? Does Singapore Airlines have a 24 hour cancellation policy? Yes, Singapore Airlines offers a 24-hour cancellation policy for tickets booked directly through their website or call center [+1-833-816-0098];. This allows you to cancel your boo... https://community.smartsheet.com/profile/204927/SIA_24hr