In 2026, the most powerful tool for cancelling a flight for a full refund is the "24-Hour (or 48-Hour) Look-in Window." Under U.S. DOT rules, any flight touching U.S. soil booked at least 7 days before departure can be cancelled for a full cash refund within 24 hours of booking. As of March 26, 2026, the India DGCA has expanded this to a 48-hour free cancellation window for domestic and international flights. If you are outside this window, you can still get a full refund if the airline makes a "Significant Change" to your schedule (usually 3+ hours domestic or 6+ hours international) or if they cancel the flight entirely. For 2026 travelers, a high-value "pro-tip" is to avoid "Non-Refundable" basic economy tickets unless you are 100% certain; instead, look for "Flexible" fares or use a credit card that offers "Cancel for Any Reason" insurance, which can protect up to 75-100% of your fare even if you just change your mind.