More than 330,000 passengers were affected by the National Air Traffic Services failure that disrupted UK aviation on September 8 and 9, according to trade body Airlines UK, which put the breakdown at over 155,000 passengers facing cancelled flights and around 180,000 experiencing delays.
That figure sits above the roughly 1,300 to 2,100 flight cancellations reported across the two days, since a single cancelled or delayed flight typically affects far more passengers than the flight count alone suggests.
As Insurance Business UK reported when the disruption was still unfolding, the Civil Aviation Authority has said the outage is likely to be classified as "extraordinary circumstances" under passenger rights rules, meaning airlines retain a duty of care but are not liable for standard cash compensation.
That classification is now pushing the practical question for hundreds of thousands of travellers away from the airline and onto their travel insurance policy specifically.
Craig Morgan, head of sales at SJL Insurance Services, said the incident should serve as a reminder for holidaymakers to check exactly what their travel insurance does and does not cover before they travel. He said a lot of travellers understandably assume either the airline or their insurer will automatically cover the cost of disruption like this, but that it isn't always that simple, since a delay or cancellation caused by something outside the airline's control, such as air traffic control failure, doesn't automatically translate into an insurance payout either.
"The biggest mistake people make is assuming all travel insurance is the same," Morgan said. "Two policies can look similar on price, but offer very different levels of protection when something goes wrong."
SJL Insurance Services set out five specific areas of a travel policy that determine whether a claim from this kind of disruption actually succeeds.
Delayed departure cover may offer a fixed payment once a flight is delayed beyond a set number of hours, but that threshold and the qualifying reasons vary by provider. Cancellation cover needs checking specifically for whether it responds to third-party disruption like this, rather than only illness, bereavement or other personal circumstances, since many standard policies are built around the latter. Missed connection cover matters for anyone travelling on separate tickets, since no statutory rebooking right applies across independent bookings if a delay causes a missed onward flight. Additional accommodation and transport cover may reimburse extra hotel stays or onward travel, though passengers should keep receipts and check whether insurer approval is needed first.
Finally, policy exclusion wording specifically around air traffic control restrictions, industrial action, airport closures and extraordinary circumstances can rule out a claim entirely regardless of the other four factors.
Morgan said anyone caught up in the disruption should keep every receipt, screenshot flight status updates, and contact both their airline and insurer as soon as possible, since the airline's duty of care, such as food or accommodation during long delays, still applies even where compensation isn't payable.
Morgan raised a specific point worth flagging for anyone travelling in the days immediately after a widely reported disruption event: buying travel insurance after an incident has already become public knowledge can mean the disruption is treated as a "known event" under the policy, potentially voiding a claim linked to it entirely.
That timing distinction matters more than usual here, given how widely this specific failure was reported within hours, and given NATS's own confirmation that recovery extended into a second day as airlines repositioned aircraft and crew.
This is the third significant NATS technical failure in three years, following the August 2023 bank holiday failure that affected more than 700,000 passengers and cost airlines an estimated £75 million to £100 million, and a further radar-related fault in July 2025.
Insurance Business UK's earlier coverage of this event focused on what that recurrence pattern means for how travel underwriters price UK aviation disruption risk going forward. The consumer-facing question SJL Insurance Services is answering here is narrower but immediately practical: for the 330,000 people actually caught up in this specific event, the outcome of any claim depends less on the scale of the disruption itself and more on which of five specific policy provisions their own insurer happened to include, a distinction that's easy to overlook when an incident this size dominates the news.
