You cannot reuse UPN for users in Project Online and Project Server 2013

Consider the following scenario:
  • User John Doe is assigned the UPN and email address of
  • John Doe leaves the company and his Active Directory user account isn't deleted.
  • is removed from the Active Directory group that's used to synchronize users to Project Web App.
  • The UPN and email address of is later reassigned to user Jane Doe.

In this scenario, the Active Directory group will successfully synchronize to Project Web App. However, Jane Doe will see the historical data for John Doe in the Project Web App (PWA).

This is by design to preserve user account history and reporting within PWA. Active Directory UPNs can't be reused for user accounts by Project Web App. 

More information
The recommendation from Microsoft Project is to not reuse UPNs within Active Directory. UPNs have to be unique within in PWA in order to function as designed. In this scenario, the AD group user seems to synchronize correctly with Project Web App (PWA). However, if the UPN already exists for a resource in PWA, it's recognized as the previous UPN and you see unexpected behavior.

For example: John Doe is an employee at Contoso, his UPN or email is His account is added to an AD group that's used to synchronize users to PWA security groups. John Doe then leaves the company, his account is deleted from the AD group, and on the next synchronization with PWA his account is marked as Inactive.  

Later, a new employee by the name of Jane Doe joins the company. At Contoso they've a policy to reuse UPNs when they're available. Jane is given the UPN or email address of Jane is added to an AD group that synchronizes with PWA security groups. When the sync occurs, PWA matches the UPN only. PWA sees that UPN already assigned to an inactive resource and links up the new AD user with the old PWA user which isn't the desired behavior. Historic data will be incorrect.
Note This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use for other considerations.

Article ID: 3174771 - Last Review: 09/30/2016 22:01:00 - Revision: 3.0

Microsoft Project Online, Microsoft Project Server 2013 Service Pack 1, Project Server 2016

  • KB3174771