Delete inactive Guest User

The script will report inactive users for x days and provides an option to delete them.

Summary

This PowerShell script identifies and optionally deletes inactive guest users in Microsoft 365. It connects to Microsoft Graph, retrieves guest users, checks their last sign-in date, and lists those who have been inactive for a specified number of days. The script then prompts the user to confirm whether to delete these inactive users.

• Open Windows PowerShell ISE or VS Code
• Copy script below to your clipboard
• Modify the $daysInactive variable as needed.
• Run the script to identify and optionally delete inactive guest users.

Warning

Please be aware this script contains a command that will remove or delete an artifact, ensure you test and understand the implications of running the script.

• Microsoft Graph PowerShell

#Install-Module Microsoft.Graph
# Define the number of days of inactivity
$daysInactive = 30

Connect-MgGraph -Scopes "User.Read.All", "User.ReadWrite.All","AuditLog.Read.All"

$calcDate = (Get-Date).AddDays($daysInactive * -1)

$guestUsers = Get-MgUser -Filter "userType eq 'Guest'" -All -Property id,displayName,mail,signInActivity,UserPrincipalName

$inactiveUsers = @()

foreach ($user in $guestUsers) {
        if ($user.SignInActivity.LastSignInDateTime -ge $calcDate) {
            $inactiveUsers += $user
        }
}

if ($inactiveUsers.Count -gt 0) {
    Write-Host "The following guest users have been inactive for $daysInactive days or more:"
    $inactiveUsers | ForEach-Object {
        Write-Host "$($_.DisplayName) ($($_.UserPrincipalName))"
    }

    # Ask if the user wants to delete the inactive users
    $delete = Read-Host "Do you want to delete these users? (y/n)"
    if ($delete -eq 'y') {
        $inactiveUsers | ForEach-Object {
            Remove-MgUser -UserId $_.Id -Confirm:$false
            Write-Host "Deleted user: $($_.DisplayName) ($($_.UserPrincipalName))"
        }
    }
} else {
    Write-Host "No inactive guest users found."
}


Disconnect-MgGraph

Check out the Microsoft Graph PowerShell SDK to learn more at: https://learn.microsoft.com/graph/powershell/get-started

Contributors

Author(s)
Peter Paul Kirschner

Disclaimer

THESE SAMPLES ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.