Entra ID Guest Accounts Can Now Have Sponsors

Defining Guest Account Sponsors with GUI and PowerShell

In July 2023, Microsoft added a new preview feature to allow organizations to assign ‘sponsors’ for Entra ID guest accounts. The idea is that an organization should be able to assign people or groups to be the sponsor of guest accounts. The sponsor should be “a responsible individual,” meaning someone who understand why a guest account is present in the directory, how that guest account is used, and what access they have to data. A sponsor can be an individual account or a group, and a guest account can have up to five sponsors (a mixture of accounts and groups).

When the time comes to review guest accounts and decide to keep or remove the account, sponsors can justify the retention of the guest account or ask for its removal. For instance, if a group owner uses a tool like Entra ID Access Review to conduct a periodic review of the membership of a group (team) and doesn’t recognize a guest account, they can contact the sponsor for more information. Whether or not the group owner gets anything useful from the sponsor is another matter.

Defining Entra ID Guest Account Sponsors

According to Microsoft’s documentation, “If you don’t specify a sponsor, the inviter will be added as a sponsor.” They then go on to explain how to invite an external user and add a sponsor to the new Entra ID guest account (Figure 1).

Adding sponsor information for a new guest account
Figure 1: Adding sponsor information for a new guest account

However, if you don’t add a sponsor to the new external account, the sponsor information is not filled in with the identifier of the account used to create and send the invitation. Maybe my tenant is missing some bits, which is entirely possible.

Sponsor information isn’t filled in either if you add a guest account by adding an external user to a team or sharing a document with them. This isn’t surprising because the sponsors feature is in preview and it takes time for applications like Teams, Outlook, SharePoint Online, and OneDrive for Business to catch up and populate new guest account properties.

In summary, if you want to update the sponsor for a guest account using a GUI, the only way is to edit the account properties in the Entra ID admin center.

Programmatic Updates for Guest Account Sponsors

A beta Graph API is available to list, update, and remove guest account sponsors. As usual, the Graph Explorer is an invaluable tool to help understand how a Graph API works (Figure 2).

Getting sponsor information for a guest account with the Graph Explorer
Figure 2: Getting sponsor information for a guest account with the Graph Explorer

The Get-MgBetaUser cmdlet from the beta module of the Microsoft Graph PowerShell SDK (now at V2.3) can fetch information about sponsors. For example, this code fetches information about a guest account including the sponsors. It then uses the Get-MgUser cmdlet to resolve the set of user identifiers into display names.

$User = Get-MgBetaUser -UserId 7bfd3f83-be63-4a5a-bbf8-c821e2836920 -Property Id, displayName, Sponsors -ExpandProperty Sponsors
ForEach ($Id in $User.Sponsors.Id) { Get-MgUser -UserId $Id | Select-Object DisplayName }

Of course, the code doesn’t handle the situation where a sponsor is a group, but that’s easily added if needed.

If you wanted to scan all guest accounts that don’t have sponsors defined and add a default sponsor, you could do something like this. The code:

  • Defines an account to be the default sponsor.
  • Builds a payload to use when updating the guest accounts.
  • Finds guest accounts in the tenant.
  • Checks each guest account for sponsors. If none are found, the script applies the default sponsor.

Connect-MgGraph -Scopes User.ReadWrite.All

$DefaultSponsorId = (Get-MgUser -UserId James.Ryan@office365itpros.com).Id
$Body = '{"@odata.id": "https://graph.microsoft.com/beta/users/' + $DefaultSponsorId + '"}'

[array]$Guests = Get-MgBetaUser -Filter "userType eq 'Guest'" -All -Property Id, displayName, Sponsors -ExpandProperty Sponsors | Sort-Object displayName
If ($Guests) {
    Write-Host "Scanning for sponsors"
    ForEach ($Guest in $Guests) {
      If ($Null -eq $Guest.Sponsors.Id) {
         Write-Host ("Guest {0} has no sponsors - updating with default sponsor" -f $Guest.displayName) 
         $Uri = ("https://graph.microsoft.com/beta/users/{0}/sponsors/`$ref" -f $Guest.Id)
         Invoke-MgGraphRequest -Uri $Uri -Method Post -Body $Body

Auditing Updates to Guest Account Sponsors

Last week I wrote about the way that Entra ID auditing does not capture details of changes to the usage location property for user accounts. As it turns out, updating a guest account with sponsor information creates an audit record without details of the change. Again, this could be a matter of timing and an update is coming to make sure that audit log events for account updates capture sponsor information correctly.

Tracking Guest Additions

Since Azure B2B Collaboration introduced guest accounts in summer 2016, administrators have been tracking the creation of guest accounts in different ways (for instance, here’s how to track the addition of guest accounts to teams). In many cases, the reason for doing so was to know who was responsible for the creation of a guest account. With sponsors, that need might go away, or at least it might be easier to retrieve the “who created that account information” by using the sponsor information stored for accounts. That is, once the apps record sponsors.

Learn about using Entra ID, PowerShell, the Microsoft Graph, and the rest of Office 365 by subscribing to the Office 365 for IT Pros eBook. Use our experience to understand what’s important and how best to protect your tenant.

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