Ryanair have said its website www.ryanair.com will close for 10 hours for maintenance.
The website will close from 7pm on Wednesday June 24, 2009 to 5am on Thursday June 25.
The budget airline said web check-in passengers travelling on Thursday, June 25, must ensure that they have checked in online before 6pm on Wednesday.
Ryanair’s website will not be available for any passenger bookings or other passenger services from 7pm on Wednesday due to these upgrade works.
Passengers who booked flights on or before the May 21 and selected to use airport check-in will be unaffected and can check-in at the airport as normal.
Ryanair’s Stephen McNamara said: "All web check-in passengers who are due to travel this Thursday should check-in and print off their boarding passes before 6pm Wednesday."