A technical glitch meant British Airways users temporarily had problems accessing the company's website and app, leading them unable to check in for trips and book flights.
However, the IT "blip" was short-lived with the airline operator reporting services were restored after around 20 minutes on Saturday.
It is also understood it did not affect all customers logging on.
During the outage, one user wrote on X: "Tried using your app and website to book a ticket for tomorrow, but it's saying it's temporarily unavailable."
Another user posted: "I can't access your website, keep getting error messages."
Responding to customers on social media, British Airways said: "We are aware of some intermittent issues with the website and app at the moment and our IT teams are currently investigating this for us."
The issue was resolved a short time later.
In May the airline cancelled dozens of flights due to IT problems - the carrier axed more than 50 departures and more than 20 arrivals in just one day.