Does a service fee apply when a 100% discount is used?

Yes, if the event offers attendees a 100% discount when using the discount code feature accessible via the registration page under the discount tab, the venue is still assessed the minimum service fee from RGS.  When a full discount is applied the service fee does not get passed onto the attendee even if the toggle to pass on the service fee to the attendee is turned on in the payment screen, so the venue may need to collect this service fee from their customer as a separate invoice after the event is over or collect this amount in advance if the event planner knows how many attendees will be using this full discount.