If you have mistakenly purchased or currently hold a child-priced ticket (ages 3–9) for a guest who is actually age 10 or older, you must complete the upgrade in person at the Disneyland Resort Main Entrance Ticket Booth. As of 2026, the Disneyland app primarily supports upgrades from standard tickets to Magic Key passes, but the "age-tier" adjustment requires a Cast Member to verify the ticket and collect the price difference between the child and adult fare. It is a "traveler's best practice" to do this before you attempt to enter the park turnstiles to avoid delays. Ensure you have your original ticket linked to your Disney account on the app for faster processing. While the upgrade itself is straightforward, you must still ensure you have a valid Theme Park Reservation for the date of your visit; usually, the reservation associated with the original child ticket will carry over once the fare difference is paid and the ticket is reclassified as an adult admission.