Efficiently Removing Inactive Guest Users in M365/Azure

At the heart of this post is Kairos IMS, an innovative Impact Management System designed to empower human-serving nonprofits and social impact organizations. Co-developed by the Urban League of Broward County and our trusted technology partner, Impactful, Kairos IMS reduces administrative burdens, enhances holistic care, and enables organizations to leverage data for increased agility and seamless service delivery. In this blog series, we’ll take a closer look at the powerful technologies that fuel Kairos IMS, from Azure services to security frameworks, offering insight into how modern infrastructure supports mission-driven impact. Click here  to learn more. 

Many organizations forget to offboard their guest users. Whether students drop out, graduate, or are removed from the program, their guest accounts often linger in your tenant—quiet, forgotten, and potentially risky.

Let’s talk about why it matters and what you should be doing about it.

The Hidden Risk of Inactive Guest Users

It’s easy to think of guest users as harmless—after all, they’re just there temporarily, right? But the reality is that each inactive user is an open door. A door that, if left unlocked, could be used by someone with bad intentions.

Here’s why:

• Their credentials may be compromised elsewhere. If a former student reused a password or their email account is breached, an attacker could gain access to your tenant through their still-active guest account.
• They may retain access to sensitive files. Even if you think they’ve moved on, inactive users might still be able to view shared documents, recordings, or internal communication threads.
• Your organization becomes a bigger target. The more accounts you have—especially inactive or unmonitored ones—the more surface area an attacker can exploit.

Nonprofits are particularly vulnerable. You’re working hard to do good in the world, but limited time, resources, and staff often mean security takes a back seat. That’s why it’s critical to develop lightweight, repeatable processes that protect your community and your mission.

Guest Access Shouldn’t Be Set and Forget

Inviting students into your tenant helps them feel part of something bigger. But just as important as the welcome is the send-off. Not everyone who starts the program finishes it, and not everyone who finishes needs continued access to your resources.

Here are a few things to consider:

• Do you have a system to track who’s still active?
• Are you reviewing guest user activity periodically?
• Do you know how to remove or disable users when they’re no longer part of the program?

If the answer to any of these is “no,” you’re not alone—and you’re not too late.

The Benefits of Cleaning Up Your Tenant

Beyond improving your security posture, removing inactive guest users can:

• Keep your environment organized. It’s easier to manage active cohorts when your tenant isn’t cluttered with outdated accounts.
• Reduce licensing conflicts. Even though guest users don’t typically consume licenses, having too many users can complicate group access, permissions, and automated workflows.
• Show respect for your participants. Offboarding users when their participation ends is a sign of professionalism—and it protects their data, too.

Up Next: How to Remove Inactive Guest Users

Now that you understand why it's important to remove inactive guest users, the next step is knowing how. Fortunately, Microsoft 365 provides built-in tools and settings to help you manage and clean up guest access safely and efficiently.

In our next section, we’ll walk you through a step-by-step guide to identify and remove inactive guest users from your tenant.

How to Create a Dynamic Group for Guest Users in Microsoft Entra ID

The first thing we need to do is create a dynamic group for guest users. This step is important because dynamic groups automatically include users based on specific attributes—in this case, identifying anyone with a user type of "Guest." Instead of manually adding or removing users from a group each time someone joins or leaves your program, dynamic groups keep everything up to date for you. It’s a simple way to ensure your access management stays clean, organized, and secure.

Step-by-Step Instructions

1. Sign in to the Microsoft Entra admin center
   You’ll need to access the admin portal to manage groups and set up dynamic rules.
   Go to https://entra.microsoft.com and log in with your admin credentials > navigate to Manage Entra ID.
   
   

    

2. Access the Groups section
   This is where all your groups are managed within Entra ID.
   In the left-hand menu, select Groups under the “Manage” section.
   
   
3. Create a new group
   This begins the process of defining your dynamic group.
   Click + New group to start creating a new group from scratch.
   
   

    

4. Configure group settings
   You’ll choose the group type, give it a name, and specify that it will use dynamic membership.
   Select Security as the group type, enter a name (like "Guest Users"), and choose Dynamic User under Membership type.
   
   

    

   
   
   
5. Add dynamic membership rule
   This is where you set the condition that defines who will be in the group.
   Under Dynamic user members, click Add dynamic query to build a rule based on user attributes.
   
   
6. Define the membership rule
   We’ll configure the rule so that it targets users where the userType equals Guest.
   Select + Add expression > set the Property to userType, Operator to Equals, and Value to Guest.
   
   
7. Add second expression to filter active guests
   This ensures only active guest accounts are included.
   Click Add expression again > set the Property to accountEnabled, Operator to Equals, and Value to true.
   
   

    

8. Validate the rules
   This helps confirm that your rule works as intended before applying it.
   Select Validate Rules > click + Add users and choose a guest user from the list.
   
   

    

9. Save the dynamic rule
   Once your conditions are set, saving them will apply the logic to the group.
   Click Save to finalize the rule and return to the group creation screen.
   
   
   
10. Create the group
    Review all the settings and create the group so it begins auto-populating.
    Click Create, and your dynamic group will now include all guest users automatically. Navigate back to the group tab > select Dynamic Groups > and select your group to view the members and verify all guest users have been added.
    
    
11. We're not done just yet! Now let's automate the review and removal of inactive guest users.

🔍 How to Set Up an Access Review for Inactive Guest Users in Microsoft Entra ID

After establishing a dynamic group for guest users, the next crucial step is to regularly review their activity. Access reviews in Microsoft Entra ID allow you to automate the process of identifying and removing inactive guest users, thereby maintaining a secure and compliant environment.

Step-by-Step Instructions

1. Access the Identity Governance section
   In the Azure search bar, type and select Identity Governance, then click on Access Reviews.
   
   

    

   
   
   
2. Initiate a new access review
   Click on + New access review to start the configuration process.
   
   

    

3. Select what to review
   • Resource type: Choose Teams + Groups
   • Review scope: Select Select Teams + groups
   • Group selection: Choose the dynamic group you previously created for guest users
   • Scope: Set to Guest users only
   • User scope: Check the box for Inactive users only
   • Days inactive: Specify the number of days (e.g., 30) to define inactivity
   
   

    

4. Configure the review settings
   • Reviewers: Select Selected user(s) or group(s)
   • Users or Groups: Select your desired reviewer(s)
   • Duration: Set the number of days the review will be open (e.g., 5 days)
   • Recurrence: Choose the frequency (e.g., monthly, quarterly) or set it as a one-time review
   • Start date: Specify when the review should begin
   • End date: Define when the review should end or select Never for ongoing reviews
   
   
   

    

   
   
   
5. Set up review settings
   • Auto apply results to resource: Enable this to automatically apply the review outcomes
   • If reviewers don't respond: Choose Remove access or Take recommendations to revoke access for users not reviewed
   • Action to apply on denied guest users: Select Block user from signing in for 30 days, then remove user from the tenant
   
   

    

6. Configure advanced settings (optional)
   • Justification required: Require reviewers to provide reasons for their decisions
   • Email notifications: Enable to send notifications to reviewers at the start and end of the review
   • Reminders: Set up reminders for reviewers during the review period
   • Additional content for reviewer email: Add any specific instructions or information for reviewers
   
   

    

7. Review and create the access review
   • Name: Provide a descriptive name for the access review
   • Description: Optionally, add details about the purpose of the review
   • Review: Ensure all settings are correct
   • Create: Click Create to initiate the access review
   
   

    

Managing guest access might feel like a behind-the-scenes task, but it plays a frontline role in protecting your nonprofit’s data, resources, and reputation. Whether a guest user is a student who graduated, a volunteer who moved on, or someone who left unexpectedly, leaving their access unchecked can expose your organization to unnecessary risk.

By creating a dynamic group for guest users and setting up regular access reviews, you’re putting smart guardrails in place. These steps not only strengthen your security but also keep your Microsoft 365 environment tidy, efficient, and aligned with best practices.

Security doesn’t have to be complicated—and it shouldn’t be an afterthought. With tools already available in Microsoft Entra ID, you can stay proactive, stay protected, and keep your mission moving forward with confidence.