How to request a same-day change or standby. After you check in, you'll receive a new boarding pass and receipt. *Customers traveling on a Basic Economy fare can't make changes at a kiosk and should find their trip on the American app, aa.com or visit a ticket counter to request a change.

Yes, you can usually perform a "Same-Day Flight Change" even after you have checked in, though the process becomes more "High-Fidelity" manual. Most major airlines like Delta, United, and American allow you to request a change via their mobile app or at a kiosk up until roughly 60 minutes before departure. If you have already checked in, the system will often "un-check" you from your original flight to move your seat to the new one. However, if you have already checked baggage, a same-day change is significantly harder and often impossible because your luggage is already integrated into the original flight’s security-screened manifest. For 2026 travelers, the "High-Fidelity" best practice is to attempt the change before dropping your bags. If you are traveling "carry-on only," you have much more flexibility to "standby" for an earlier flight or confirm a new seat at the gate, provided you meet the airline's specific elite status or fare-class requirements for a same-day move.