How to: Set Up Guest Users in Microsoft Teams (Cross-Tenant Access)

Overview

Inviting a guest from another Microsoft 365 tenant into your Teams workspace requires updates to three key admin areas. This guide outlines the exact steps to enable guest collaboration across tenants.

Step 1: Configure External Access in Teams Admin Center

1. Navigate to the Microsoft Teams Admin Center

2. Go to Users > External Access

3. Set external access policies:

   
   

   • To allow all domains, toggle “Allow all external domains” to On

   • If restricting domains, specify which domains to Allow or Block

   
   

4. Save your changes

Step 2: Set Up Cross-Tenant Access in Microsoft Entra

1. Open the Microsoft Entra Admin Center (formerly Azure AD)

2. Go to External Identities > Cross-Tenant Access Settings

3. Add the other organization by:

   
   

   • Entering their domain name or tenant ID

   
   

4. Configure collaboration settings to be Permissive (or set restrictions if needed)

5. Under External collaboration settings, review and allow guest invitations and interactions

Step 3: Invite the Guest User

1. Still in Microsoft Entra, go to Users > New External User

2. Click Invite External User

3. Enter:

   
   

   • Their email address

   • Display name

   
   

4. Send the invitation

What Happens Next

• The invited user receives an email to accept the invitation.

• After acceptance, it may take up to 2 hours for the guest to be fully registered.

• During this time, Teams chats sent to the guest will be routed via email until setup is complete.

• Once complete, the guest will appear in:

  
  

  • Microsoft Teams (under “Guest Users”)

  • Microsoft 365 Admin Center (under “Users > Guest Users”)

  
  

Need Help?

If your guest isn’t showing up after a few hours, double-check:

• Domain allow/block settings in both tenants

• Cross-tenant policies for collaboration in Microsoft Entra

• Whether the guest has accepted the invite