RBD — Reservation Booking Designator

RBD — Reservation Booking Designator

The RBD (also called booking class or fare class) is the single-letter code that underpins airline inventory management. While passengers see cabin labels like Economy or Business, the airline's systems work at the RBD level — controlling price, availability, mileage accrual and upgrade eligibility.

Common RBD Conventions

By convention (though not mandatory across all airlines): Y and B typically denote full-fare economy; M, H, Q, V, W lower economy fare classes; J and C business class; F first class. The specific fare and rules attached to each RBD are defined by the airline's revenue management team and filed with ATPCO.

RBD and Yield Management

Revenue management systems open and close RBDs dynamically based on demand and remaining capacity. As a flight fills up, lower RBDs (cheaper fares) are closed and higher RBDs remain open. This is the mechanism through which the same seat on the same flight can be priced at vastly different levels.

RBD and Frequent Flyer Accrual

Mileage accrual rates are typically defined by RBD, not by the fare paid. A Y-class ticket may accrue 100% of miles flown while a Q-class ticket on the same route accrues only 25%, even if the price difference is small.

RBD in GDS

When a GDS displays availability as Y4 B0 M2 Q9, the letters are RBDs and the numbers indicate how many seats are available in that class (or that availability is being actively controlled by the airline).