As airline seats shrink and comfort plummets, more travelers are considering an unconventional solution: buying an extra seat for personal space. But can you actually guarantee that middle seat stays empty, or will airlines reclaim it if the flight fills up?
A couple planning a long-haul flight posed this question to Reddit's travel community: "We were thinking that perhaps we could buy an extra seat 'between us.' My question is, would the airline essentially fill that seat if it is empty?"
It's a reasonable concern. Paying several hundred dollars for an empty middle seat feels wasteful if the gate agent can reassign it at boarding. But the answer depends entirely on the airline and how you purchase that seat.
The official policy: Most major airlines do allow passengers to purchase additional seats for comfort, though policies vary significantly. The seat is typically purchased under a name like "EXTRA SEAT" or the passenger's name with a specific notation. When done correctly, the airline cannot reassign that seat to another passenger—it's been legitimately purchased.
Here's what works:
U.S. carriers: Airlines like Delta, United, and American allow extra seat purchases but require calling the reservation line rather than booking online. You'll need to explain you're purchasing an adjacent seat for comfort. The agent will create a reservation with a notation that prevents the seat from being reassigned. Expect to pay the full fare for that seat—no discounts for buying multiple seats on one ticket.
Southwest Airlines has the most accommodating policy: passengers of size who require two seats can purchase both upfront, then request a refund after travel if space was available. They also allow anyone to purchase additional seats for comfort or belongings.
International carriers generally permit extra seat purchases but policies vary widely. Some Asian and Middle Eastern carriers are more accommodating for comfort seat purchases, while European low-cost carriers may not allow it at all.
The key detail: you must inform the airline during booking. Simply buying three seats under three different names doesn't work—the airline will see empty seats and may reassign them during check-in or at the gate. The reservation must be properly annotated to prevent this.

