Understand linked subscriptions
When a contact (person or organisation) owns a subscription it will appear in the Owned subscriptions section on their contact record. In this case, the amount and renewal date are displayed indicating this person is responsible for the subscription.
Linked joint or proxy subscriptions
When a person is linked with a subscription owned by another person (i.e. a joint or proxy membership subscription) the subscription will appear in the Linked joint/proxy subscriptions section. The owner and status are displayed. To add more joint members you need to go to the subscription itself, or the owner's contact record.
When a person is linked with an organisation the organisation will appear in the Linked organisations section. By default, a person does not gain member status when linked with an organisation. To grant a person member status you need to edit the link and choose to also link the person with the organisation's subscription.