On United Airlines, Class Z is a revenue booking code for Discounted Business Class. When you see "Z" on your ticket, it means you are seated in the United Polaris (international) or United First (domestic) cabin, but you purchased the ticket at one of the lowest available business-class price points. While you receive the full premium experience—including lie-flat seats, premier check-in, and Polaris lounge access—Class Z tickets are typically non-refundable or carry much higher change fees than full-fare "J" or "C" classes. In 2026, Class Z is also known for having lower MileagePlus accrual rates; while you still earn a significant number of miles, it is often less than what a full-fare business passenger would receive. For those looking to upgrade using miles or PlusPoints, Class Z is often the target for "Instant Upgrade" promotions, offering a luxury experience for a fraction of the standard premium price, provided the traveler can tolerate the lack of ticket flexibility.