UK transport networks have been thrown into chaos by the global IT outage.
There are long queues at airports, while trains are also disrupted because of the problem.
Transport Secretary Louise Haigh said her department is “working at pace with industry and across Government on the issue”.
Consumer group Which? advised airline passengers to avoid checking in luggage if possible.
Microsoft is currently experiencing a global outage which is impacting select systems at Heathrow. Flights are operational and we are implementing contingency plans to minimise any impact on journeys. Please check with your airline for the latest flight information. pic.twitter.com/s6Psd6pHUB
— Heathrow Airport (@HeathrowAirport) July 19, 2024
Long queues formed at airports such as Gatwick, Luton and Edinburgh.
Ryanair advised passengers to arrive at airports early as it switched to manual check-in.
A traveller at Gatwick Airport said he had been queuing for more than three-and-a-half hours ahead of a flight to Miami, Florida.
Dean Seddon, 42, from Plymouth, told the PA news agency: “There are just people everywhere, there must be 400 people in this queue for the check in desk I’m at… it’s just bedlam.
“It’s one of those things where you kind of know we’re not going to fly, but you don’t want to leave because you don’t know.
“(Staff are) doing the best they can but they don’t actually know when it’s going to be fixed, so it is frustrating, but you kind of feel for the staff as well.”
The couple are booked to fly to Paris to mark their 55th wedding anniversary by going on a cruise starting on the River Seine.
Mr Spraggons said: “The biggest problem is the lack of information. We got here and we didn’t know what was happening until we saw the queues.”
A spokeswoman for Heathrow, the UK’s busiest airport, said the outage was “impacting select systems”.
She went on: “Flights are operational and we are implementing contingency plans to minimise any impact on journeys.”
The queue at Stansted snaked outside the main terminal building.
The business student, from Romford, east London, said their Ryanair flight taking them on an eight-day holiday to Magaluf, Spain, was due to leave at 12.40pm and they had arrived at 9am.
She said she had heard “nothing” from the airline and “we had no warning of this”.
Rory Boland, editor of magazine Which? Travel, said passengers due to travel today “will naturally be deeply concerned”.
He went on: “If you can, avoid checking in a bag as queues for check-in at the airport will be long and IT failures typically lead to lots of lost bags.
“If you do check-in bags, make sure you keep medication, keys and any other essentials in your hand luggage.”
He said passengers will not be eligible for compensation for delayed or cancelled fights due to the “extraordinary circumstances”, but airlines have a duty to look after them, including providing meals, accommodation and alternative flight bookings if necessary.
We are affected by the global Microsoft issues, so passengers may experience some delays while checking in and passing through security.
Passengers should still arrive for their normal check-in time. We apologise for any inconvenience and are working to resolve the issue as… pic.twitter.com/T9adpYELxW
— London Gatwick LGW (@Gatwick_Airport) July 19, 2024
UK air traffic control provider Nats said its systems are “operating normally”.
Friday is the busiest day of the year so far for UK air travel with 3,214 departing flights as thousands of families embark on summer holidays at the end of the academic year for many schools.
Aviation analytics company Cirium said 1,396 flights have been cancelled globally, including 43 UK departures.
Several US carriers have grounded flights, including United, American Airlines and Delta.
Train service information website National Rail Enquiries warned passengers there are “widespread IT issues across the entire network”.
Among the operators affected are Avanti West Coast, Great Western Railway, Southern and Thameslink.
National Rail Enquiries said: “Some train operators are unable to access driver diagrams at certain locations, leading to potential short-notice train cancellations.
“Additionally, other key systems, including real-time customer information platforms, are also affected.”
South Western Railway said all its ticket vending machines had stopped working due to IT issues.
It advised passengers to “purchase your ticket online, on the train or speak to a member of station staff”.
Industry body the Rail Delivery Group said “most trains are still running across the country”.
Ms Haigh said: “We are aware of IT failures impacting several transport operators and terminals today, and we’re working at pace with industry and across Government on the issue.
“There are no known security issues at present.
“If you’re planning to travel today, please follow operator advice and check ahead before leaving.
“Manual check-in may be required at airports and there may be flight and train cancellations and delays.”
