What is UPN (User Principal Name)?

Sometimes users in an AD, or those on the O365 cloud find it difficult to log in to their accounts. After exhausting the attempts, when they approach the admin, they get the response that it “it is due to an invalid UPN”. To clear out the confusion, admins have to explain what is User Principal Name and do so in an easy-to-understand manner.

Table of Contents

• What is UPN
• UPN & Email Mismatch Challenge
• Check the UPN
• Troubleshoot Issues
• Conclusion
• FAQs

The traditional understanding is that the UPN is just the name of the user in an email address format. Although that’s not wrong, the real definition of UPN is a bit more complex. Therefore, we present this write-up that gives readers a breakdown of the UPN definition. On top of that, you get to explore its significance, functionality, and best practices for managing it in Office 365 or Active Directory.

Explanation of What is User Principal Name Done Right

Let’s take a look at what a typical UPN looks like

FirstName.LastName + @ + DomainName.com

This is the format prescribed in the RFC 822 document. From Microsoft’s point of view, it is a standard attribute present in all user accounts.
When we look closely, we can see that it is made of two parts. The first of which is the prefix. It is always the name of the user (it may be a combination of initials, first name, and/or surname). Second part contains the organization’s domain name server (DNS) address. Here, the “@” symbol acts as the connector to join both halves and construct the UPN.

Also Read: Admins Active Directory Security Best Practices Checklist

What Happens If Office 365 Users have Different Primary Email and UPN

As it has been discussed earlier, there can be situations when the login UPN and primary email address does not match. In that case, users may face difficulties accessing different Office 365 applications. Here, we will provide a list of situations when the confusion regarding UPN may occur:

• Office subscription-based activation
  – The end user has to provide their UPN, and NOT their email address for authentication.
• Skype for Business
  – To authenticate, UPN has to be entered.
  – Though the default Session Initiation Protocol (SIP) address in MS Office 365 is UPN, users can change this manually.
• Office 365 Web Portal
  – UPN should be used to authenticate in place of email address.
• Exchange ActiveSync (EAS)
  – In this case, also, users must use their UPN. EAS profile’s automatic configuration requires users to input on a second screen.
• Office Mobile Applications
  – The end-user should provide their UPN rather than their email address to access mobile applications of Office 365.

How to Verify or Modify Office 365 user UPN

After learning what is user principal name the next natural step is to find it.  This helps admins diagnose user login problems right at their source. Depending on your setup there are two ways to check the UPN.

• Microsoft Office 365
  In Order to Check UPN address present in Office 365 (assigned to every new user by default), go to Microsoft 365 admin center. Then click on Users > Active users.
• Active Directory PowerShell Module
  

  Get-ADUser  -Filter * -Properties userPrincipalName| Select-Object Name, UserPrincipalName

Also Read: Learn What is Active Directory Migration In Simple Words

Note: Both the cloud and on-premise setups allow users to exist without a UPN. So that might be the reason why you get a blank result.

Troubleshoot User Principal Name Issues

If Office 365 users face the problem when UPN contains domain.onmicrosoft.com format in place of your domain’s suffixes (e.g. my-organization.com), they have to edit UPN address. For this, take the help of Azure Active Directory Module for Windows PowerShell.

1. To import Azure Active Directory Module for your PowerShell:

   import-module MSOnline

2. To connect to Office 365 by running this cmdlet:

   $msolcred = get-credential
   
   connect-msolservice -credential $msolcred

3. To change the UPN address of the user:

   Set-MsolUserPrincipalName -UserPrincipalName -NewUserPrincipalName

• Microsoft Exchange Server

In Exchange, follow these steps to check or change a UPN.

1. Launch Active Directory Users and Computers on the domain controller (DC) machine. Right-click on the mane of any users and click on Properties.

2. Select the Account tab and go to the User login name section to change the UPN.

import-module activedirectory
Get-ADUser -Filter * -SearchBase 'ou=,dc=,dc=' -Properties userPrincipalName |

foreach { Set-ADUser $_ -UserPrincipalName ("{0}@{1}" -f $_.name,"")}

Conclusion

Now users have in-depth understanding of what is User Principle Name in Office 365 and AD. With this knowledge, admins can level up the user experience and keep loin failures at a minimum. Here we went over the importance of a standardised UPN structure. Following it should be a core component of every digital security checklist.

Frequently Asked Questions

Q. 1 What is the difference between a UPN and an email address?

Usually, there is no surface-level difference between the two. Meaning that UPN and email look the same but they have different roles. The former is used for entering into your account, while the latter is for sending and receiving mail.

Q. 2 How do I change a UPN in Office 365?
Administrators can change UPNs through the Office 365 admin center or using PowerShell scripts for bulk changes.

Q. 3 Can a user have multiple UPNs?
No, each user can only have one UPN, but they can have multiple email aliases.

Q. 4 Why did my UPN change after a domain name update?
UPN changes often occur after domain updates to reflect the new domain structure. This ensures consistency and correct routing of authentication requests.

Q. 5 How do UPN changes affect user login?
UPN changes require users to update their login credentials across all devices and applications. Proper communication and guidance can help mitigate any confusion.