The FAIR Fees Act of 2026 would require airlines to limit fees charged to passengers to amounts that are reasonable and proportional to the actual costs the airlines incur. The bill directs the Secretary of Transportation to establish regulations within 270 days that set standards for evaluating airline fees related to reservation changes or cancellations, baggage handling, seat selection, priority boarding, and other flight-related charges. The regulations would require airlines to account for factors such as their ability to resell seats, processing costs, and labor expenses when determining whether fees are justified. The bill also includes a specific requirement that airlines must allow parents to seat children age 13 and younger next to them at no extra charge. The Secretary would be required to review and update these fee standards at least every three years to ensure they remain appropriate.