This section of the Membership Product editor allows you to require another product to be added at checkout with the product they are purchasing. This is an important setting for products that are intended for new members, since the required secondary product could be the Initiation Fee product or other first year dues. You can add up to two required products…
The checkbox titled “Only require if not a member” would allow you to sell the same product, for example “Family Membership” to both a member and non-member, but only add an Initiation Fee to the cart if the buyer is not a current member.
This setup can be a great way to minimize the number of membership-producing / renewing products your club sells. Notice in the example screenshot below, this club makes it clear the Initiation Fees will only be added if the buyer is new.