You can use promo codes to restrict who can see what kind of registration type (or ticket type.)

Promo Codes

Promo Codes can be used in Grenadine to allow specific users (those who have been given the promo code) to view ticket types that are not visible or available to the general public. These can include but are not limited to, add-on tickets for spouses, tickets for specific sessions, etc. Promo codes can also be used if you are organizing an event that is invitation only to ensure only those you have sent the promo code to will be able to purchase tickets. Please note that “promo codes” in Grenadine cannot be used to offer a discount. To create a discounted ticket (student, early bird, etc.) you need to create a discounted ticket type. In order to create a promo code you must first create the “ticket type” it will be attached to