Password Manager Pro licensing is based on two factors:
Number of Administrators
Type of Edition - MSP Standard Edition or MSP Premium Edition
Note:
Password Manager Pro comes with four user roles - Administrator, Password Administrator, Password User & Password Auditor. The term 'administrator' denotes both Administrators & Password Administrators. So, licensing restricts the number of Administrators AND Password Administrators. There is no restriction on the number of Password Users and Password Auditors. You can also store and manage unlimited passwords.
MSP Standard Edition - If your requirement is to have a secure, password repository to store your passwords and selectively share them among enterprise users, Standard Edition would be ideal.
MSP Premium Edition - Apart from storing and sharing your passwords, if you wish to have enterprise-class password management features such as remote password synchronization, password alerts and notifications, application-to-application password management, reports, high-availability and others, Premium edition would be the best choice.