United's new policy is made possible through a series of investments in a new seat map feature that dynamically finds available adjacent seats at the time of booking. The online seat engine first reviews all available free Economy seats and then opens complimentary upgrades to available Preferred Seats, if needed.
Customers traveling with children under 12 will start to see more adjacent seat options immediately and the complete policy change will go into effect in early March.
In instances when adjacent seats are not available prior to travel – due to things like last minute bookings, full flights or unscheduled aircraft changes – United's new policy also lets customers switch for free to a flight to the same destination with adjacent seat availability in the same cabin. Customers also won't be charged if there is a difference in fare price between the original and new flight.