Dropbox for Business accounts can have any number of administrators, each able to update and change billing information from the Upgrade page. However, each administrator is restricted from seeing the billing information of other administrators. All sensitive information, such as credit card numbers, are left blank for any user other than the one who entered the information in the first place.
This article refers to a feature unique to Dropbox for Business. Dropbox for Business is aimed at projects, groups, and other organizations that want to share the same Dropbox storage quota with all of its members. If you're interested in learning more or want to sign up, visit the Dropbox for Business webpage.