The comments section for each expense allows a two-way interaction between the approver and employee. If there are any clarifications on an expense, use the comments section to ask a question. Comments added to the thread are notified through an email to the user. (Click here to learn how to reply to comments from within the email using dynamic emails feature in gmail)
To add a comment to the comment thread of an expense:
Click on the expense on which you want to add a comment. '
On the right hand side, click on the Comments bar. This will show up the Comments thread.
Click on the History button on the right hand side of an expense to view the complete trail of actions performed on the expense.