NATS System Failure, September 2026: Are You Owed Compensation?

On 8 September 2026, a fault in National Air Traffic Services' flight data processing system forced a wider shutdown of parts of the network, triggering restrictions on air traffic across the UK. Cancellations climbed through the day, past a thousand by evening, and the cumulative total across the following days is reported to have exceeded 2,000 flights. Heathrow, Gatwick, Stansted, Manchester, Birmingham and Edinburgh all reported disruption. Ryanair alone cancelled around 260 flights affecting roughly 48,000 passengers, and British Airways cancelled close to 200.

What actually caused it

NATS has said the fault originated with a single flight plan, reportedly filed by a military aircraft, that contained unusual or "spurious" data the system wasn't able to process correctly, causing a wider shutdown of the affected system as a safety measure. NATS has stated this was a different underlying fault to the flight data system outage in August 2023, though the visible effect on passengers, mass cancellations and delays, looked similar. The Civil Aviation Authority has been asked to conduct an independent review, and NATS was given a week by the government to report back on what happened.

Does a NATS system failure count as extraordinary circumstances?

This is the question that determines whether you're owed fixed cash compensation on top of a refund or rerouting. A fault originating inside NATS' own systems, rather than an external event like weather, is a genuinely difficult case, and it's likely to be argued both ways. NATS is not the airline you booked with, so an airline can reasonably argue the failure was outside its own control and unforeseeable, which is the core test for extraordinary circumstances. Whether that argument succeeds can depend on the specific findings of the CAA's review once published, and on how any test cases arising from this event are eventually decided.

What's not in dispute is that this being extraordinary circumstances, if it's found to be, would only remove the fixed compensation payment. It doesn't remove anything else airlines owe you.

What you're owed regardless of how "extraordinary circumstances" is eventually decided

• A full refund of the cancelled flight, or rerouting to your destination at the earliest opportunity or a later date of your choosing
• Meals and refreshments proportionate to your wait, if you're stuck at the airport
• A hotel and transfers if an overnight delay results
• Reimbursement of reasonable receipted expenses if the airline failed to provide the above and you had to pay for it yourself

These duty-of-care obligations apply regardless of the cause of the cancellation, including a genuine third-party technical failure like this one. Airlines dealing with a network-wide event of this scale sometimes struggle to deliver care on the ground in real time, but the legal obligation doesn't lapse because the disruption was widespread.

If your cancellation had a different, unrelated cause

Not every cancellation on 8 September, or over the following days as the network recovered, was necessarily caused directly by the NATS fault. Knock-on effects, aircraft and crew out of position, meant some cancellations in the days that followed had their own separate causes. If your specific flight was cancelled for a reason unconnected to the NATS event, that flight is assessed on its own facts, not automatically covered by whatever applies to the NATS outage itself.

How to claim

Klaimly checks your specific flight and cancellation reason against what's known about this event before advising whether fixed compensation is realistically claimable, and pursues the refund, rerouting, and expense obligations regardless. We handle the process for a flat 5% fee, only if we win. No VAT, no minimum fee, and nothing to pay unless your claim succeeds.

Sources: NATS technical issue updates, Al Jazeera.