Article ID: 2428507 - View products that this article applies to.
In Microsoft Office 365, you receive an error message that's like the following in the Microsoft Office 365 portal:
A user with this name already exists. Use a different name.
This issue may occur if the user name is already used or if an existing email address that's based on the user name already exists.
The licensing attempt will fail if the provisioning process determines that another object already has a user name or an email address that matches the user name that's being created.
By default, when users are added or assigned an Exchange Online license, the users are provided with a primary SMTP address that's based on their user name. And, users are provided with an email address that's based on the Microsoft Online Direct Routing Domain (MODRD) such as, for example, contoso.onmicrosoft.com. Additionally, when a user name is changed, the primary SMTP address may also be changed. However, alternate addresses aren't updated or removed.
Here are some example scenarios.
A user is added who has a user name of firstname.lastname@example.org, the MODRD for the organization is contoso.onmicrosoft.com, and the user is assigned an Exchange Online License. In this scenario, the following email addresses are provided:
A user is added who has a user name of email@example.com, the MODRD for the organization is contoso.onmicrosoft.com, and the user is assigned an Exchange Online License. In this scenario, the following email address is provided:
A user name is changed from firstname.lastname@example.org to email@example.com. In this scenario, the following events occur:
To fix this issue, do one or more of the following:
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