This incident has been resolved.
Sep 15, 13:00 BST
A fix has been implemented and we are monitoring the results.
Sep 15, 12:10 BST
We are working on implementing a fix for this issue.
Sep 15, 11:30 BST
Our development team have identified the cause and are working to fix the problem. Thank you for your continued patience.
Sep 15, 10:30 BST
We are aware that some of our clients have been unable to access their accounts. We are currently investigating the issue and working to resolve this issue as soon as possible. More updates to follow.
Sep 15, 09:31 BST