Analysing data from January to September, Aviation experts at AirAdvisor have determined which airline was the 'most unreliable' for UK travellers in 2025 - and it may not be the one you're thinking of.

As per an analysis of Civil Aviation Authority (CAA) figures, published last month, TUIwas found to be the least reliable airline in terms of punctuality, with 57.5 per cent of its flights departing on schedule - less than half. Meanwhile, a lesser-known airline tied in the top spot with Virgin Atlantic for most reliable, with 81 per cent of flights running on time.

With the poorest average performance based on the available 2025 data, TUI has been dubiously crowned the worst airline for flight delays in the UK, while other trusted major airlines also saw frustrating delays. Blue Airlines, which has since gone bust, came in a close second for tardiness, managing an on-time rating of under 60 per cent in 2025, whilst Swiss Airlines fared slightly better with roughly 64 per cent of their services running to time this year.

Bottom 3:

1. TUI

2. Blue Islands

3. Swiss Airlines

Top 3:

1. British Airways, Wizz Air, Emerald Airlines, Lufthansa and United Airlines

2 Emirates

3. Loganair and Virgin Atlantic

• 'I quit my London job to live in a van by the coast - now I spent £10 at weekends'

At the opposite end of the spectrum, Virgin Atlantic and Loganair jointly claimed the crown for punctuality, with an impressive 81 per cent of flights departing on schedule in 2025, reports Birmingham Live. Across the board, the combined average on-time performance for all carriers stood at 72 per cent during the same reporting window.

AirAdvisor's research focused on the 20 airlines handling the highest passenger volumes at UK airports each quarter, monitoring the percentage of flights that experienced delays based on CAA records. Under CAA guidelines, a flight is classified as "on-time" if it arrives at or departs from the airport gate within 15 minutes of its scheduled slot.

CAA officials routinely gather punctuality statistics from the largest UK airlines operating across Britain. Anton Radchenko, CEO of AirAdvisor, explained: "Many factors contribute to an airline's on-time performance, not all of them within an airline's control, but past performance remains a key indicator of a carrier's future ability to keep flights on schedule.

"TUI's on-time performance in quarter three, which includes the months of July and August, is traditionally poor - this is unfortunate given how many people go on holiday at this time of year. In fact, CAA data suggests that in quarter three of 2024 and 2023, less than half of TUI services in the UK were on time.

"While that figure increased to 55 per cent in quarter three of 2025, it's still significantly lower than Virgin Atlantic and Loganair's 82 and 78 per cent respectively, in the same period. Airlines that score consistently high on-time percentages during more challenging spells are more likely to keep passengers moving to schedule during less busy times of the year.

"British consumers should be relieved to hear that, in the most part, flight delays and cancellations are falling, and 2025 has been something of a turning point year for the aviation industry, with disruptions finally decreasing to close to pre-COVID levels.

"That said, millions of passengers each year find themselves in a position where their flights are delayed or cancelled. And in many cases, you may be due up to £520 in compensation for the inconvenience caused, thanks to UK government regulation UK261, depending on the cause of the disruption and the notice you were given by your airline."

The worst-performing airlines, ranked by average punctuality from January to September of 2025, where at least two quarters of data were available, are as follows:

1. TUI – 57.5 per cent of flights on time (average of Q2 and Q3 as data unavailable in Q1).

2. Blue Islands** – 59.5 (data unavailable in Q1).

3. Swiss Airlines - 64 per cent of flights on time.

4. KLM and Jet2 - 69 per cent of flights on time.

5. Ryanair - 70 per cent of flights on time.

6. Air France - 71 per cent of flights on time.

7. easyJet - 72 per cent of flights on time.

8. American Airlines and Vueling - 74 per cent of flights on time.

9. Eurowings and Aer Lingus - 75 per cent of flights on time.

10. British Airways, Wizz Air, Emerald Airlines, Lufthansa and United Airlines - 76 per cent of flights on time.

11. Emirates – 78 per cent of flights on time (average of Q1 and Q2 as data unavailable in Q3).

12. Loganair and Virgin Atlantic - 81 per cent of flights on time.

Do you have a story to share? Email me at julia.banim@reachplc.com

• 'My top winter buy is on sale - a self-heating blanket that costs nothing to run'