United Airlines Will Sell You a Row With No Middle Seat—Here’s the Catch

United Airlines is testing a new way to make flying a little more comfortable—and a lot more expensive. The carrier announced Tuesday that select rows on its upcoming Airbus A321XLR jets will feature an empty middle seat, replaced by a shared tray table for the aisle and window passengers. These premium-economy-plus seats land later this year, and United hasn’t yet said what the upgrade will cost. If the experiment works, the airline may add the feature to other long-range narrow-body planes.

This upsell is the latest in a wave of a la carte pricing sweeping the industry. Just last week, Delta Air Lines followed United’s lead by rolling out stripped-down business-class and premium-economy fares. Under the new structure, Delta’s cheapest long-haul business tickets no longer include lounge access or advance seat selection—benefits that were once standard. The message is clear: if you want the extras, you’ll have to pay for them separately.

United isn’t stopping there. In March, the airline revealed plans for a “Relax Row” on some wide-body aircraft—a set of three economy seats that fold flat into a bed. Airlines have been packing in more premium seats for years, betting that travelers will keep spending on comfort even as fares rise. The trend has gotten so elaborate that seat manufacturers are struggling to keep up, and the bottlenecks have delayed deliveries of new planes. For passengers, the takeaway is simple: the days of the standard seat may soon be over.