Energy firm Npower has closed their app due to an attack which exposed some customers’ financial and personal information, contact details, birth dates, addresses and partial bank account numbers are included in the details stolen.

The company did not give a statement about how many accounts were affected by the breach, but Npower said the affected accounts had been locked, according to BBC news.

“We’ve contacted all affected customers to make them aware of the issue, encouraging them to change their passwords and offering advice on how to prevent unauthorized access to their online account.” The company said in a statement.