Ryanair has confirmed that its website and mobile app will close for 12 hours for a systems upgrade.
The services will be taken offline from 17:00 on Wednesday, November 7th, until approximately 05:00 on Thursday, November 8th.
Passengers were warned online check-in will not be available during this period.
Ryanair spokesman, Robin Kiely, said: “As part of our continued digital development, a web closure and system upgrade will take place for 12 hours.
“Flight bookings and changes will also be unavailable during this period.
“Customers travelling on Wednesday or Thursday should check-in for their flight on Tuesday, November 6th.
Ryanair has today contacted all customers booked to travel on Wednesday and Thursday by email and SMS text to advise them to check-in online for their flight on Tuesday, before the above web closure takes place.
New bookings or changes to existing flights will not be possible during this web closure.