Create Event Invoices using integrated Billing module

If a payment method of Invoice is selected, this invoice will be queued and then created at a time of your choosing. If a payment method of Credit Card is selected, one of three results will happen depending on your choice: an invoice and payment will be automatically created, a sales receipt will automatically be created, or no transaction will happen. Make these selections for each event on the Fees tab of the desired Event.

Event invoices may be created from within the Events module or from the Billing module. Either way of creating invoices accomplishes the same task.