Union allows admins to add a one-time charge (i.e cancelation fee). We do encourage you to notify your students that this will be implemented.
While on the performance registration page (or directly from the users Union profile):
Click their name in bold
Click the drop down arrow next to "Edit" and select "Payment Card"
Enter the dollar amount with any additional notes and the click "Charge Card"
*Note: The exit icon button while on the Register, this will take you to your previous page (i.e. performance registration list, students profile).