The Information Commissioner’s Office said it will make enquiries after receiving numerous complaints from angry consumers.The data protection watchdog told the BBC: “Businesses should only contact individuals for electronic marketing purposes where consent has been provided or, in limited circumstances, where they have an existing relationship with a customer.

“Some members of the public have made us aware of an email sent by Klarna and we will be making enquiries.”With more than 3 million active users in the UK, Klarna is the leading global payments provider. The service allows shoppers to ‘buy now and pay later’ and its checkout technology is used by a large number of fashion retailers including Asos, H&M, Nike and Abercrombie & Fitch.In a blog post, the company apologised for the “mistake”, saying it was a “human error”.“The email was sent to Klarna consumers who have recently used one of Klarna’s products or services including Klarna’s checkout technology. When you use Klarna you agree to our terms and conditions and our privacy notice,” it said. The company explained that it processes all credit and debit card transactions for its retail partners, which gives it access to customer data that is used for “several purposes” like fraud detection.“Please rest assured, you have not been added to a marketing database. In accordance with our internal policies you will not receive any further newsletters unless you opt in or download our app at a later date,” it said.“We are currently investigating how this happened, and are taking action to ensure nothing like this can happen again in the future.”