Ryanair customers will not be able to check in online or make new bookings for a ten hour period on Friday evening due to an upgrade of the airline’s online system.

Ryanair.com and the Ryanair mobile app will both go offline from 7pm Irish time on Friday until 5am on Saturday morning to allow for the upgrade.

The airline is to contact those travelling on Friday or Saturday to inform them of the downtime and is asking customers to check in for their flight by tomorrow evening to avoid any issues.

Ryanair said it would not be possible for people to make new bookings, or amend existing bookings, during the upgrade and apologised for any convenience caused.