Australian online retailer Princess Polly is the latest to suffer a security breach.
In an email to customers, CEO Wez Bryett advised customers that an unidentified third party recently gained unauthorised access to its website.
"During this process, the third party may have accessed your personal information entered on our website," he wrote.
This included billing and shopping name, address, email, phone number, date of birth as well as user name and password.
"As soon as we became aware of this incident, we took immediate steps to investigate and confirm that our website was secure.
"We have appointed external IT and Cyber Security consultants to fully investigate this incident."
He said experts have confirmed that its website is secure, including any personal or payment information provided when shopping with Princess Polly.
"We take the protection of our customers' data very seriously and have further strengthened our security measures to ensure that our customers' information is secure."
Last year, US-based equity firm Elevate Brandpartners took a 50% stake in Princess Polly with plans for a international rollout.
Outdoor retailer Kathmandu is also among clothing brands to suffer a security breach this year.