You can invite a family member to your Home subscription, as long as the subscription has free spots (max 5).
To invite a new member go to Settings and Family members.
Choose how you want to send the invitation: Send email or Send SMS and add their email-address or phone number.
You can also copy an invitation URL from this page and send to the person you want to invite if you do not wish to invite via email or SMS.
The person receiving the invite can choose to:
Join by creating a new user account
Join with an existing account
If they join by creating a new account they will inherit the storage from the Home subscription.
If they join with an existing account, your existing subscription will be replaced with the Home subscription. All the files on your account will remain on your account, as before.
The Home subscription owner is the only one who can add and remove members.