When trying to create, rename, or restore a user in the Admin console, you might receive the error message "Username already exists." This typically occurs for one of the following reasons.
A user, alias, or group already exists with that username
For example, a deleted user might have been re-created (either by an admin or due to a directory sync application). If you then try to restore the deleted user, you'll see the message.
To check for the existing username and remove the conflict:
Type the name you're trying to create, rename, or restore in the search box at the top of the Admin console and click the Search icon.
- Click on the name of the user or group that currently uses this name.
- Change the user or group name to a different name. If an alias is using the desired name, go to User information Email aliases and remove the alias.
- If you renamed the existing user in the previous step, go to User information Email aliases and remove the email alias created by the user rename process. When you change a user's primary email address, G Suite retains the old address as an email alias for the user, to ensure continuous mail delivery. Therefore, if you want to re-use the old address, you first need to delete the email alias. See impact of renaming a user to learn more.
There's a conflicting account when you haven't verified your domain
We recommend that you verify domain ownership. During this process, conflicting accounts are renamed automatically if they conflict with a new user that you're trying to add in G Suite.
Note: If you’re trying to add a username that was used as an alias in another G Suite domain in the last 24 hours, you may need to wait for 24 hours before a new account or alias can be created with that email. Learn more