They are using Altea software and there are several airlines that use the same software for check-in and it's that which is affected.
Amadeus operates global booking systems for travel and offers airlines a check-in service.More news: Roku Prices Shares at $14, Valuing Company at $1.3 Billion
Lufthansa, Air France and Southwest Airlines all reported check in delays due to the outage. As a result of the incident, customers experienced disruption to certain services.
"Altea" software which is used by 125 airlines is responsible for the problem.
Amadeus competes with Sabre Corp. and Travelport Worldwide Ltd.in booking systems, with the Spanish company claiming a 43 percent market share. A problem with Delta's system grounded flights across the world in January, while a problem with the British Airways system caused thousands of cancellations in May.More news: Ringgit lower against United States dollar in early trade
"This is an airline issue", he said, adding that there had been no major delays caused.
Long check-in lines were a common sight for passengers all over the world Thursday.
A spokesman for Heathrow Airport, which is Europe's busiest and serves London, said that a "small number of airlines" were experiencing "intermittent issues" but that passengers could still check in for their flights.More news: Backed Militia Says It Has Recaptured Syria's Biggest Gas Field from ISIS
Passengers are seen waiting to check in for flights at London's Heathrow airport in this file pic. That action is ongoing with services gradually being restored. Although the network problem has been resolved by Amadeus, airports are cautioning customers that the backup may linger as providers try to get back on track.