If the membership of your family members is setup as a single family, the adult will usually be granted access to the minor's membership details, so that you may file claims or review claims outcome on their behalf.
However if your dependents are above 18 years old, the access will not be granted automatically.
This is the case as well between you and your spouse as BUPA regard you as adults and you should have control over who have access to your private information.
This can be frustrating if you are tasked to be the administrator of the membership for everyone in the family.
The good news is that this rectified by getting the members in your family to explicitly grant you access to their membership.
This can be done getting them to log onto your their respective membership world portal and click on "Your Profile" on the top right hand control of the screen
Thereafter, the adult member may grant access by checking off the following checkboxes.