WH Smith has said Funky Pigeon, its greetings card subsidiary, fell victim to a cyber security incident last week.
In an update on the London Stock Exchange, the stationary giant said orders from the Funky Pigeon website have been temporarily suspended.
The online retailer was affected by an incident on Thursday 14 April.
Customer payment data, including bank account or credit card details, has not been placed at risk. However, WH Smith said it was currently investigating the extent to which any personal data, “specifically names, addresses, e-mail addresses and personalised card and gift designs” has been accessed.
“We would like to sincerely apologise to our customers for any concern or disruption this may cause, and reassure them that our teams are working around the clock to investigate and resolve this incident,” a blog post from Funky Pigeon stated.
The company said it was currently unable to fulfil orders while it worked with external IT specialists to investigate the incident and restore services.
Every shopper from the past 12 months would be contacted to be informed of the issues, the firm added.
WH Smith said the incident would not have a material impact on its financial position, ahead of reporting its results later this month.
The high street retailer’s share price fell more than 1.5 per cent in early trading on Tuesday.