Self-assign an expense report
By default, new reports are set to Unassigned. Use the Assignee field and select your name from the Assignee drop-down menu to assign an expense report to yourself or to assign it to other auditors. The Assignee list includes all the auditors assigned to the report’s Audit Profile.
Reports assigned to other auditors are available as Read Only. You can assign them to yourself or unassign them to make them editable.

Note
No notifications are sent when a report assignment changes. You can complete an audit on an unassigned report.
Additional Information
The experience is covered in more detail in the Concur Expense Tools Guide for Verify