Reusing UPNs for users in Project Online and Project Server 2013 causes problems


Consider the following scenario:
  • User John Doe is assigned the UPN and email address
  • John Doe leaves the company, but 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 (PWA).
  • The UPN and email address 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 Project Web App (PWA).


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

More Information

We recommend not reusing UPNs in Active Directory. UPNs have to be unique in PWA to function as designed. In the problem scenario, the AD group user seems to synchronize correctly with Project Web App. However, if the UPN already exists for a resource in PWA, the UPN is recognized as the previous UPN, and unexpected behavior occurs.

For example: John Doe is an employee at Contoso. His UPN or email address 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 reuse UPNs that are available. Jane is given the UPN or email address 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 as 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.

Article ID: 3174771 - Last Review: Oct 11, 2016 - Revision: 1

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