While you can technically return earlier, you cannot simply "show up" at the airport with your original ticket; you must officially change your flight with the airline. In 2026, most airlines allow changes to round-trip tickets, but the cost depends heavily on your "fare class." If you purchased a "Basic Economy" or "Non-refundable" ticket, you will likely be charged a change fee (ranging from $75 to $200) plus the "fare difference" between your original ticket and the new, likely more expensive, last-minute flight. If you have a flexible or "Refundable" fare, you might only pay the fare difference. A major trap to avoid is "skip-lagging" or simply missing your scheduled return flight to book a new one; if you don't cancel your original return properly, the airline might cancel the rest of your itinerary or refuse to credit your miles. Always check the "Manage Booking" section of the airline’s app to see the real-time cost of moving your return date up, as many airlines in 2026 have simplified their digital tools to allow for instant, self-service flight swaps.