How Often Do Airfares Change, and What Does Changing a Flight Cost? Monthly Airfare Movements, Change-Fee Revenue, Cancellations and Passenger Compensation from BLS, BTS and Regulatory Data, 1964–2026

Airfares are widely believed to change constantly, yet no official statistic counts fare updates. We use the monthly consumer price index for airline fares (BLS, 1964–2026) to describe how often, how much and when the going price of air travel moves, and set it against airline change and cancellation fee revenue (BTS Form 41 releases, 2011–2025), flight cancellation rates (BTS on-time data, 2004–2026) and published compensation rules. Over September 2016 to August 2026 the index moved by 0.05% or more in 116 of 118 measurable months, rising in 64 and falling in 52, with a median absolute move of 2.86%, or 1.35% after seasonal adjustment. The share of falling months rose from 5.8% in 1969–1978 to 45.7% in 2020–2025. In 13 normal years July was below June every time, by 5.7% on average, and the January level sat 13.3 points of the annual average below May. After general inflation, airfares in 2025 were 42.7% below their 2000 peak, but May 2026 was 26.7% above May 2025. Change and cancellation fee revenue fell from USD 3,011.8 million in 2015 to USD 1,053 million in 2025, from 1.78% to 0.4% of operating revenue, after the largest carriers dropped change fees on standard tickets. In 2025, 1.53% of scheduled arriving US flights were cancelled, against 5.99% in 2020. US rules require refunds but no cash compensation for delays, whereas the EU pays up to USD 682.02 (EUR 600). All inputs are public.