Revolut customers have been hit by a fresh security incident after the broker the fintech uses to trade US stocks suffered a breach, emails seen by Sifted show.

The incident involved unauthorized access to customer data, including personal and financial information. Revolut confirmed the breach occurred through a third-party trading partner and that affected customers were notified.

A Revolut spokesperson said, "We take the security of our customers' data extremely seriously and are working closely with our partners to investigate this incident fully." The company has also advised users to monitor their accounts for suspicious activity.

This is the latest in a series of security challenges for Revolut, which has rapidly expanded its user base and product offerings across Europe and beyond. Regulators in the UK and EU have previously flagged concerns over the fintech's risk management practices.

Revolut currently serves over 30 million users globally and has been valued at $33 billion. The company is pushing to become a full banking license holder in multiple jurisdictions.