IHG Hotels and Resorts has revealed that parts of its technology systems have been “subject to unauthorised activity”.

The hotel group’s booking channels and other applications have been experiencing significant disruptions since Monday. Guests may experience challenges booking a new reservation, accessing information about an upcoming stay or accessing the IHG One Rewards account.

In a statement on Tuesday evening, the group said:

“IHG has implemented its response plans, is notifying relevant regulatory authorities and is working closely with its technology suppliers. External specialists have also been engaged to investigate the incident.”

It added that it will aim to “fully restore all systems as soon as possible” and that it will be supporting hotels owners and operators. Hotels are still able to operate and to take reservations or cancellations directly by telephone.

ihg.com