Error Creating New SQL User – The Server Principal Already Exists

You are trying to create a new SQL user, and you receive the following message, “the server principal ‘xxxx’ already exists’ as below:

Ok, maybe that user already exists.  You search SQL Management Studio, but cannot find the user associated with any databases or under the main Security node.

You can run the query below to check first:

However, you don’t find the user in question anywhere with the login name.

Let’s try a different query and look at the ID’s:

Note the SID that is returned.

Now query the sys.server_principals table again but using the SID:

You will find that the SID is related to another user.  You can now research this user.  Many times it’s related to an old windows user account.  If so, you can delete that user.  Then try adding your new user again.

Note: We’ve see this happen with Dynamics SL and Windows Authentication.  A new user is set up using an existing Dynamics SL user.  Instead of creating a new SL user, the administrator takes an existing user and changes the Windows User Account to the new one.  Be sure to set up the new user as its own user in Dynamics SL.

If you’re having SQL troubles, we can help.  Email us at

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