Up to 2.4 million customers are at risk after a sophisticated cyber-attack on the Carphone Warehouse.
The phone company has revealed that the stolen data may include names, addresses, dates of birth and bank details.
Encrypted credit card information of approximately 90,000 customers may have also been accessed by the hackers.
Sebastian James, group chief executive of Dixons Carphone, said: “We take the security of customer data extremely seriously, and we are very sorry that people have been affected by this attack on our systems.
“We are, of course, informing anyone that may have been affected, and have put in place additional security measures.”
An investigation into the security breach, which was discovered on Wednesday, is ongoing.
