Understanding Teams guest access vs. external access

Trying to decide if you should use Teams guest access or external access? That depends on how your organization treats external users in Microsoft Teams. Guest access supports collaboration inside a team, including channels, chat, meetings, and files for ongoing project work. Guests are added to your organization's Microsoft Entra ID as B2B collaboration users, giving them access to the team's connected resources.

External access, on the other hand, lets your users find, call, and chat with people in other Microsoft 365 organizations without adding them to a team.

Other options like SharePoint and OneDrive include their own external sharing settings that let users share sites, folders, and files with people outside the org. IT admins manage these separately within the SharePoint admin center, though organization-level settings in Microsoft Entra ID can also apply.

Before you start using Teams with external users, think through your governance needs and what actions you’ll need to take to keep your environment secure. After all, what gets created today will eventually need review in the future—a task that falls right on your desk as an IT admin.

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What’s external access in Microsoft Teams?

With Microsoft Teams external access, users can call, chat, and set up meetings with people outside their organization who use Microsoft as an identity provider. Meaning, employees can start 1:1 chats and schedule meetings with external users. Access is mainly managed through the Teams admin center, and you can choose which companies to allow or block entirely from your environment. 

Remember that people outside your organization aren’t added to your Microsoft Entra tenant, and they won’t be able to access any of your Microsoft 365 tools. This includes your Team channels or the linked SharePoint site details. 

Usually, external access configuration works best for:

• Vendor communication
• Cross-company chats
• Quick coordination with partner organizations
• Meetings without shared workspace access

In short, external access gives you a communication layer across your workplace. When chats and meetings are the goal, external access is the right choice.

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What’s guest access in Microsoft Teams?

Guest access lets owners and admins invite an external party to collaborate directly. After being added to a team, guests get access to resources based on permission settings for that team, including channels and other apps tied to it. These are adjustable by using tools like SharePoint or company policies. 

Once you add a guest, their access stays until someone removes them from the team. Even then, the guest account stays in your Microsoft Entra ID until an admin explicitly deletes it. Over time, this can create governance risk if guest identities aren’t reviewed regularly. 

For example, guests may unintentionally collect memberships in different teams and Microsoft 365 groups. This can give them access to SharePoint sites and other resources they don’t need anymore or shouldn’t have access to. Unfortunately, these reviews don't happen automatically —the risk will sit there until someone looks into it. But without a deliberate review process in place

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Teams guest access vs. external access

Here’s a comparison between models:

Key takeaway: While external access lets people communicate, guest access allows for more collaborative work. Learn more in Microsoft’s documentation on using guest access and external access to collaborate with people outside your org. Unfortunately, people coming in and out creates constant openings that IT teams need to check and manage. When communication is all that’s needed, using guest access means you’re taking on governance overhead without any real benefit.

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Best practices for managing external and guest access in Microsoft Teams

To keep your environment secure, IT admins need to set up and check the settings for sharing with people outside of the organization. Below are a few best practices for making access management easier.

Align guest access configuration across workloads

If one workload is more limited than another, guest collaboration can fall apart. For example, a guest invitation may work in Teams, but the user might not be able to open files if SharePoint external sharing isn't enabled in the SharePoint admin center or if Microsoft 365 Groups isn't configured to allow guests to access group content (both are separate settings that Teams doesn't control directly)..This is a common challenge for IT teams, especially since controls live scattered across admin centers rather than in one place.

Proper guest access includes aligning settings across:

• Microsoft Entra External ID for B2B collaboration settings
• Teams admin center for guest permissions and policies
• Microsoft 365 Groups settings for guest membership
• SharePoint admin center for external sharing settings that affect connected team sites

Be intentional about setting up external access

External access is on by default and is primarily configured in the Teams admin center (though Microsoft Entra ID settings can override it). This means your users can communicate with people from other organizations without a complicated setup. While this is convenient, it also means access can sprawl if not actively supervised. Review which domains to trust and if audit logs or settings drift over time. This lets you avoid sharing content with any vendors you no longer work with or companies that don’t exist anymore. 

If communication is your end goal, this is the right model for chat and meeting scenarios since it avoids creating access to your workspace that needs governing.

Manage SharePoint external sharing separately

SharePoint, managed in the admin center, has its own rules for sharing files, folders, and sites with people outside the organization. It handles:

• Company-wide external sharing settings
• Default link types (Specific people, Anyone with the link, Only people in your organization)
• External sharing levels (Anyone, New and existing guests, Existing guests, Only people in your organization)

Since Teams stores files in SharePoint, these settings affect every team-connected site. It’s possible to limit Teams guest access but still allow external sharing through the site. For example, someone could get blocked from joining a team as a guest but still receive a sharing link to files in the team’s SharePoint site.

Review guest identities and memberships

Someone who left a vendor organization months ago could still have access to files they shouldn’t see. To avoid unnecessary data exposure, review identities in Microsoft Entra ID, Microsoft 365 group memberships, and SharePoint access tied to those groups. From there, decide whether each guest still needs access.

For external access, make sure to regularly review:

• Trusted domains
• Federation settings
• Policy alignment

Get a clearer picture of who has access across your tenant

Native controls and configurations spread across:

• Microsoft Entra admin center
• Teams admin center
• Microsoft 365 admin center
• Microsoft 365 Groups settings
• SharePoint admin center

With so many dashboards, it’s hard to figure out at scale which guests are in your tenant and where they belong. It’s also difficult to find existing external sharing links, trusted access domains, and where exposure is highest.

So as an admin, you’re jumping between apps instead of seeing data all in one place. And this issue only gets worse when users constantly create teams and share files. With strong IT governance, you can reduce friction and keep the collaboration environment productive. 

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Strengthen external access governance with ShareGate Protect

Answering governance-based questions is frustrating with your controls spread across various admin centers. ShareGate Protect replaces that fragmented picture with a single operational governance layer across your Microsoft 365 environment, so you can:

• Identify guest access drift
• See oversharing and unsafe external access patterns across Teams, SharePoint, Groups, and OneDrive
• Understand what's exposed and why it matters with severity indicators and impact context
• Fix issues quickly with in-context remediation—no scripts, no admin-center hopping

For IT admins, that means less manual work, clearer visibility, and a faster path to secure collaboration and Copilot readiness. 

Request a demo today, and see how ShareGate can simplify the way you govern guest access.