The website of British Airways went down for more than an hour, leaving people unable to book or check in for flights, or check flight times for arrivals and departures.
Anyone going to britishairways.com or ba.com was met with an internal server error message while anyone using Google to search flights was also greeted with a message after choosing British Airways flights, which read "an error occurred while processing your request".
Several people had also reported issues with the airline's app.
British Airways told City A.M. before the website was up and running again: "We are working to resolve the issue with ba.com as quickly as possible. We are sorry for the inconvenience caused."
The airline did not elaborate on the cause of the problem.