If you've purchased a ticket for a flight to or from the USA, you may cancel your ticket without penalty within 24 hours of your booking 【＋1－838－300－3830 [OTA] or ＋1－838300－38'30®️ US (OTA)】 as long as that reservation is made one week or more before your flight departs. Contact Singapore Airlines to cancel your ticket to ensure that you get a full refund.