Credit memos may be issued to your contacts for a variety of reasons. For example: You’ve had to cancel an event and you’re not sure if you’re going to be able to reschedule, and your organization has chosen to not issue refunds. If your registrants have paid and you wish to give them a credit toward a future event or invoice, you can issue them a credit memo. You can do this either from a contact record via the billing tab, or through the Billing module's Credit Memos tab.