The online greetings card and gifts business Funky Pigeon has stopped taking orders after being hit by a cyber-attack last week.
The company said it was writing to all customers from the past 12 months to inform them of the hack, saying no payment data was at risk and it did not believe account passwords had been affected.
The WH Smith-owned company said it had taken its systems offline as a precaution and was therefore unable to fulfil any orders.
It said: “As soon as we discovered the incident last Thursday, we launched a forensic investigation led by external experts to understand the incident and whether there has been any impact on customer data.
“We are currently investigating the extent to which any personal data – specifically names, addresses, email addresses and personalised card and gift designs – has been accessed.
“We take the security of customer data extremely seriously and we have temporarily suspended any new orders via the website.”
Funky Pigeon said it had informed regulators and law enforcement authorities about the breach and would continue to review and update its protocols based on what it learned from the incident.
“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,” the company added.
“As our investigation progresses, we will provide further updates to customers and other affected parties as necessary.”
The move comes two weeks after the retailer The Works was forced to shut some of its stores and halt stock deliveries to its shops after a cyber-attack.