Airlines must now show bag and seat fees before the fare. Bookings shifted within a week.

A rule requiring airlines and booking sites to display baggage and seat-selection fees alongside the fare — on the first page of results, not after selection — took effect this month. The behavioral effect showed up almost immediately.

Data shared with MNC News by three booking platforms covering the first full week shows the lowest headline fare capturing about nine percentage points less share than in the equivalent week before the rule. That share moved to itineraries that were more expensive on the fare line and cheaper once bags and seats were included.

Who gained without doing anything

The carriers that gained most did not change their prices. They were the ones whose fares already included a carry-on and a seat assignment, and whose all-in total had always been competitive but had never been the number shoppers saw first.

The carriers that lost share were those with the lowest fares and the most unbundling. Two have since begun advertising bundled fare families more prominently, which is a pricing change in presentation rather than in substance.

We did not get cheaper. We stopped competing against a number that was never the real number.— A revenue manager at a mid-sized carrier

What is not covered

The rule reaches carry-on, first checked bag and advance seat selection. It does not reach change fees, priority boarding, or the fee some carriers charge for a boarding pass printed at the airport. Consumer groups have asked for those to be added; carriers argue that a disclosure listing every optional service becomes unreadable.

• Requirement: carry-on, first checked bag and seat selection fees shown with the fare
• Early effect: lowest headline fare lost about 9 points of booking share
• Winners: carriers whose fares already bundled bag and seat
• Not covered: change fees, priority boarding, airport boarding pass fees

One week is not a trend, and the platforms cautioned that the sample covers a period with unusually light business travel. The direction, though, matches what economists predicted: when the comparison unit changes, the ranking changes, and prices follow the ranking.