All about managing external users in Microsoft Teams

Microsoft Teams governance

External collaboration is essential in modern workplaces, yet managing external users remains challenging. According to research, 71% of the companies surveyed remove their external users from their teams manually.

What does external access mean?

External access in Microsoft Teams enables collaboration with users outside your organization through two mechanisms: Guest Access and External Access. These approaches allow external participants to use organizational accounts without creating new user profiles, reducing licensing costs while improving user experience.

The primary risk occurs when external sharing processes aren't defined. Organizations lose visibility into which documents external users access, creating data security vulnerabilities.

External access vs. guest access

External Access: Grants external users domain access for Teams chat while restricting file sharing outside direct conversation contexts.

Guest Access: Invites external users directly into Teams, providing access to all stored team data.

Options for external access settings

Azure AD

Active Directory portals enable guest user management and organizational relationship configurations, allowing team owners and members to invite guests independently.

Microsoft Teams Admin Center

The admin center manages organization-wide guest access settings through toggles and feature controls, though standard Microsoft tools offer limited governance options.

Microsoft 365 Admin Center

Security and Compliance settings activate external sharing; Office 365 Groups settings provide two checkboxes controlling guest access and owner invitation permissions.

SharePoint Admin Center

Administrators can transfer external permissions to Azure organizational relationships or maintain independent guest lists. Selecting existing guests restricts to Azure-stored users; selecting Everyone enables anonymous sharing.

External users need to be managed carefully

Unmonitored external user access creates serious data protection risks. Upon project completion, external users should be immediately removed. Failure to do so results in unintended persistent access to team communications and shared information.

Additionally, organizations must verify non-disclosure agreements remain current with external collaborators. Without signed NDAs, third parties access company data without contractual obligations.

What should you avoid from an IT perspective for the administration of external users?

Creating internal company accounts for external users introduces significant problems. While simpler for occasional collaborations, this approach generates unnecessary licensing expenses. High-volume external user turnover rapidly escalates costs. External users typically prefer using personal accounts, and creating corporate credentials reduces response times and collaboration effectiveness.

Why external user management in Microsoft Teams is awkward

External user removal requires manual intervention across individual teams, as memberships lack time restrictions. Effort increases proportionally with user volume. While invitations are straightforward, ongoing management demands substantial administrative resources.

Issues with corporate accounts for external users and alternatives for collaboration with external users

Internal company accounts require continuous monitoring, removal, and reassignment — demanding coordination between IT and departments. Additional licensing expenses accumulate; external users often resist corporate accounts, negatively impacting collaboration responsiveness. Accounts created but never removed from teams result in permanent unauthorized data access.

Manage external users on the basis of standard Microsoft tools

Azure AD's Access Review feature can analyze and automatically remove external users, though requires manual administrator configuration and Azure AD P2 licensing — often unavailable in mid-sized organizations. A dedicated tool for automated access-review campaigns removes both the licensing hurdle and the manual configuration effort.

Azure AD P2 Advantages and Disadvantages

Advantages: Provides comprehensive visibility into user activity across Azure, Office 365, and web applications; enables comprehensive user management and SSO access control; offers identity protection and privileged identity management.

Disadvantages: Requires separate directory service integration; cloud-focused organizations may struggle with implementation; lacks RADIUS network access management and comprehensive system management features.

Recommended approaches to managing external users

Organizations should implement domain whitelisting, inviting external users with their own accounts rather than creating internal profiles. Establish automatic membership expiration (7, 30, 90, or 180 days) with user-controlled extension, shortening, or removal options. Standard Microsoft tools cannot implement this approach — a dedicated way to manage guest users in Microsoft Teams, covering whitelisting, time limits, and automatic removal, is necessary.

Type of external users

Define which external users may be invited. Distinguish between existing external users (already in Active Directory or approved domains) versus new unknown addresses. Categorize teams according to security requirements rather than applying blanket policies. Align security levels with intended usage purposes.

Setting up guest permissions for a team

Implement document classification using sensitivity labels to control external user access levels. Analyze team workspaces to identify external users, then remove them as standard practice.

Conclusion

Limited resources may justify implementing governance solutions that automate the policies discussed. These platforms enable temporary access configuration, restrict external users to authorized data, and automatically revoke permissions based on defined conditions.