Answer: there can be several reasons why a membership is not showing online.
The first thing to check is that the Membership IS available to some customers.
If not, please check that you have completed all the steps in this article.
Once you have confirmed all the steps have been taken and only some customers can't see the membership online, it's likely because they are logged into their account and are not eligible to purchase the membership.
Is the setting 'Display Ineligible Membership Types' enabled? Please see our article on how to change Membership Settings.
If the setting is enabled, and the customer is logged in but not eligible to purchase the membership, check that the customer has 'Show Ineligible Memberships' ticked.
In the example below, due to their age, the customer is not eligible to purchase the Youth Membership. Therefore, it won't show by default.
Once ticked, the membership will appear, greyed out.