An assessment of flight data spanning from January to September 2025 by AirAdvisor’s aviation experts has revealed the airline that performed the worst in terms of reliability for UK travelers. Contrary to popular belief, TUI emerged as the least dependable airline, with only 57.5% of its flights departing on time. In comparison, a lesser-known carrier shared the top spot for reliability with Virgin Atlantic, both achieving an impressive 81% on-time departure rate.
TUI’s consistently poor performance throughout 2025 has earned it the title of the worst airline for flight delays in the UK. Notably, Blue Airlines, now defunct, closely followed TUI with an on-time rating of under 60%. Swiss Airlines showed slightly better punctuality, with about 64% of their flights operating on schedule during the same period.
The top three most reliable airlines, each boasting an 81% on-time departure rate in 2025, were Virgin Atlantic and Loganair. On the other end of the spectrum, the worst-performing airlines, based on average punctuality from January to September, were as follows:
1. TUI – 57.5% on-time flights
2. Blue Islands – 59.5% on-time flights
3. Swiss Airlines – 64% on-time flights
4. KLM and Jet2 – 69% on-time flights
5. Ryanair – 70% on-time flights
6. Air France – 71% on-time flights
7. easyJet – 72% on-time flights
8. American Airlines and Vueling – 74% on-time flights
9. Eurowings and Aer Lingus – 75% on-time flights
10. British Airways, Wizz Air, Emerald Airlines, Lufthansa, and United Airlines – 76% on-time flights
11. Emirates – 78% on-time flights
12. Loganair and Virgin Atlantic – 81% on-time flights
AirAdvisor’s analysis focused on the 20 airlines with the highest passenger volumes at UK airports, monitoring flight delays based on CAA records. Flight punctuality is defined by CAA as arriving or departing within 15 minutes of the scheduled time. CEO Anton Radchenko emphasized that an airline’s past performance is a crucial indicator of its future ability to maintain on-time flights, despite external factors influencing punctuality. He highlighted the improving trend in flight delays and cancellations, signaling a positive shift in the aviation industry in 2025.
Passengers experiencing flight disruptions may be eligible for compensation under UK government regulation UK261, up to £520, depending on the cause of the disruption and notification by the airline.