What is my user ID and why do I need it?

Updated: September 15, 2015

Applies To: Azure, Office 365, Windows Intune


This topic provides online help content for cloud services, such as Microsoft Intune and Office 365, which rely on Microsoft Azure Active Directory for identity and directory services.

A user ID is required by every user in your organization that needs to sign-in to any Microsoft cloud services that you have subscribed to.

What is a user ID?

Each user ID has a user principal name (UPN) suffix associated with it that is constructed using the account’s User Name (which must be unique) attribute value, the @ symbol, and the Internet domain name value that was assigned to it by an administrator when the account was created in Azure AD. For example, a user ID could be PierreSettles@contoso.com. To determine the user ID for a user, in the Azure Management portal, click the name of the directory and then click the Users tab. The User Name column lists each user ID.

The domain you assign to a user ID can be either the default “.onmicrosoft.com” domain is assigned by default when you first sign up for a Microsoft cloud service or another domain name that you have registered.

If you want your user ID and email address to use your custom domain—such as nicolep@treyresearch.com—instead of the initial onmicrosoft.com domain, add and register another domain.

Why do I need a user ID?

From an end user point of view, you will need to have a user ID in order to sign in to the cloud services that your organization has subscribed to.

From an administrator’s perspective, you will need to create user IDs for each user that requires access to the Microsoft cloud services that you have subscribed to. Azure AD generates a temporary password for each new user, along with each user’s user ID, so they can sign in to cloud services that you have assigned those licenses to. You can think of user IDs as being similar to standard on-premises user accounts in that you can assign different levels of permissions or roles to each user ID in your directory.

By default, the user ID specified by the person who created your organization’s directory will automatically be granted global administrator permissions so that user has full access to directory resources such as users and groups. For more information about global administrator permissions, see Assigning administrator roles.

How user IDs are used during the sign-up process

The act of subscribing to a Microsoft cloud service such as Microsoft Intune or Microsoft Office 365 for the first time automatically creates an Azure directory that makes it possible for you to administer a single set of user accounts across one or more Microsoft cloud services that your organization has subscribed to. For more information, see What is an Azure AD directory?.

During the sign-up process you must specify:

  • A new domain name that is unique to your organization.

  • An existing email address as your alternate contact email address.

  • A new user ID that will be used by that person to sign-in to your new directory.

After you complete the signup process, you’ll get an introductory email message at your existing email address that includes your user ID and the URL of the page where you will sign in to the cloud service. If you forget your user ID, or if you don’t remember the URL of the portal, look at the introductory email message to find this information.


The alternate email address you are asked to provide during the signup process is used for important communications, such as administrator password resets. Information about service and billing, and promotional information that you choose to receive, will also be sent to this email address. If you are an administrator, you can change this email address on the Profile page.

Using your existing user IDs across multiple Microsoft cloud services

If you already have a directory with established user IDs and you want to subscribe to additional Microsoft cloud services, it is recommended that you use your same user ID when you sign-up for any new Microsoft cloud service so that you can leverage the same group of user IDs across all the services that your organization subscribes to. If you use a different user ID to sign up for another Microsoft cloud service, a new directory will be created. For more information, see What is an Azure AD directory?.

Community resources

See Also


Administering your Azure AD directory

Other Resources

Create or edit users
Add your domain