Monday's technical failure at National Air Traffic Services was the third disruption of its kind in three years and the second inside a month.
Each time it happens, the same question resurfaces for a client holding a standard travel policy: does their cover respond to an air traffic control failure at all, and did anyone check that before they bought it.
Nats attributed Monday's disruption to a "connectivity issue" at its Prestwick centre, which manages about 42% of UK air traffic across Scotland, Northern Ireland and northern England.
It said the fault had "nothing to do" with a software defect at its Swanwick centre weeks earlier, which the company later said occurred "in the space of a millisecond" and corrupted underlying data.
A separate failure on September 8 grounded more than 1,300 flights in a single day, with a further 177 cancelled the following day, a scale comparable to Nats' 2023 bank holiday failure, which cost airlines more than £100 million in refunds and compensation.
Read more: NATS glitch cancels more than 1,300 UK flights as insurers assess claims
Monday's disruption was smaller but still substantial. Cirium recorded 140 cancelled departures and 137 cancelled arrivals; easyJet lost 48 of 670 scheduled flights, British Airways 13 of 513, and Ryanair reported 140 flights and 25,000 passengers affected.
The Civil Aviation Authority said the fault is "likely to be considered the result of 'extraordinary circumstances' under passenger rights rules," meaning airlines owe stranded passengers care but not cash compensation. That leaves the cost of onward accommodation, rebooking and missed connections to whatever travel policy those passengers hold.
Not every travel policy responds to an air traffic control failure. Admiral's Enhanced Trip Disruption option and Post Office's equivalent both name airspace closures, air traffic control restrictions and technical problems as covered events, which indicates the risk can be underwritten when a provider chooses to include it.
Many standard policies do not carry that wording, which means two clients affected by the same Nats outage could receive different outcomes depending on which policy they were sold.
With three Nats failures in three years, the argument that this risk is rare or unpredictable becomes harder to sustain with each repetition.
A client whose claim is declined because their policy excludes air traffic control failure has grounds to ask why that exclusion was not raised when the policy was recommended or renewed.
Travel was the only UK general insurance line where complaints rose in the second half of 2025, up 19.4% while every other line fell.
Ombudsman referrals for travel insurance climbed 58% year-on-year in the third quarter of last year, one of the highest totals outside the immediate post-Covid period.
Those figures predate Monday's disruption and reflect existing pressure on the product, into which a further wave of Nats-related claims and complaints is likely to land.
Read next: Travel insurance complaints rise as Ombudsman referrals reach post-COVID levels
The Financial Conduct Authority has flagged claims handling and consumer understanding as travel insurance priorities running through 2026, and travel insurance evidence has also featured in a House of Lords inquiry examining how well home and travel cover serves consumers.
Under the Consumer Duty's fair value rules, insurers are expected to justify why a product is priced and designed as it is; whether an exclusion for a risk that has materialised three times in three years was made clear to customers at the point of sale is the kind of question that framework invites, though the regulator has not commented on Nats specifically.
A comparable pattern appeared in July 2024, when an IT outage grounded flights and insurers said they expected a related rise in claims. That event and the current Nats disruptions share a structural feature: a single cause outside any traveller's control generating a large number of simultaneous claims, rather than the individual, unconnected losses travel insurance has traditionally been priced around.
The UK travel insurance market totalled roughly £980 million in premiums in 2024, with ABI members paying out £472 million across more than 500,000 claims that year.
Set against that scale, a wave of claims tied to a single Nats failure remains a fraction of overall volume, though the pattern of repeat events raises the question of whether it should continue to be treated as an isolated disruption category or as a recurring one.
The CAA's independent review into Nats' resilience is due to report "within six months." Its findings will address the infrastructure side of the problem.
The separate question of whether current policy wording, and the advice given at the point of sale, adequately reflects a risk that has now recurred three times in three years remains open, and is likely to surface again the next time a Nats system fails.
