Passengers are most commonly upgraded to business class through "operational upgrades" (often called "op-ups"), which occur when the economy cabin is oversold but there are empty seats in the premium cabin. To maintain the flight schedule without bumping passengers, the airline moves people forward. These upgrades are almost always prioritized based on an elite status hierarchy; a "Diamond" or "Platinum" frequent flyer will always be moved before a general member. Other reasons include "Service Recovery," where an airline provides an upgrade to compensate for a significant past inconvenience, or "Inoperative Seat" issues, where a passenger's original economy seat is broken. Additionally, some travelers are upgraded because they used "Upgrade Certificates" or miles to waitlist for a better seat. While rare, "weight and balance" requirements on smaller aircraft can occasionally force a move, but in 2026, the majority of "free" upgrades are a strategic reward for loyalty or a logistical necessity to manage an overbooked plane.