Forum Discussion
B2B Direct Connect and File Sharing Support
Microsoft Support Team,
We are configuring Microsoft Entra B2B Direct Connect between three separate Microsoft 365 tenants:
NorthstarTech.example
BluePeakSystems.example
CedarBridgeGroup.example
Each organization has its own tenant and native user accounts. For example:
alex.morgan@northstartech.example
alex.morgan@bluepeaksystems.example
alex.morgan@cedarbridgegroup.example
These are separate native accounts, and we want to maintain them in their respective home tenants.
Primary Requirement
Our objective is to use Microsoft Entra B2B Direct Connect while maintaining each user's existing identity in their home tenant and avoiding the creation of additional Guest accounts.
We want to understand the capabilities and limitations of B2B Direct Connect when used with Microsoft Teams, particularly regarding one-to-one chats, domain trust recognition, and file sharing.
Current Issues
Teams one-to-one chat trust recognition
When initiating one-to-one Teams chats between users from our separate tenants, we want the domains to be recognized as trusted.
Currently, Teams displays a message indicating that the domain is not on the trusted domains list.
We would like to understand how Microsoft Entra B2B Direct Connect and Teams can recognize these organizations as trusted without requiring us to manually add each domain to the trusted domains list in the Teams Admin Center.
Our goal is to determine whether the existing cross-tenant access configuration can provide the necessary trust recognition, or whether the Teams external access domain allowlist must also be configured.
Teams chat file sharing
After configuring B2B Direct Connect, we encountered an issue with file sharing in Microsoft Teams chats.
When communicating with users from a trusted tenant, drag-and-drop file sharing does not work as expected.
We would like Microsoft to clarify whether this behavior is expected with B2B Direct Connect or whether additional configuration is required.
Questions for Microsoft Support
B2B Direct Connect and file sharing
Does Microsoft Entra B2B Direct Connect support file sharing in Microsoft Teams chats, including drag-and-drop functionality?
One-to-one chat and trusted domain recognition
How can we configure Teams so that one-to-one chats recognize our domains as trusted instead of displaying the message that the domain is not on the trusted domains list?
Can this be achieved through Microsoft Entra cross-tenant access settings and B2B Direct Connect without manually adding each domain to the Teams Admin Center trusted domains list?
Required configuration
Are additional settings required in any of the following services to enable the expected functionality?
Microsoft Entra ID and cross-tenant access settings.
Microsoft Teams external access.
Teams Admin Center domain restrictions.
SharePoint and OneDrive sharing settings.
B2B Direct Connect configuration.
Domain trust and tenant relationships
Can Microsoft Teams automatically recognize an organization as trusted based on the existing B2B Direct Connect relationship, or is the Teams external access domain allowlist managed independently?
If these configurations are independent, what is the recommended approach to avoid maintaining duplicate domain allowlists where possible?
Guest-free configuration
Can these capabilities be enabled while keeping users as native accounts in their respective tenants and avoiding the creation of Guest accounts?
Product limitations and recommended approach
If trusted domain recognition or drag-and-drop file sharing is not supported through B2B Direct Connect alone, please confirm the applicable product limitations and recommend the Microsoft-supported configuration that best meets our requirements.
Important Requirements
Our requirements are:
Maintain separate native user accounts in each tenant.
Avoid creating additional Guest identities.
Enable one-to-one Teams chats between users in the separate tenants.
Understand how to achieve trusted domain recognition without manually maintaining the Teams Admin Center trusted domains list, if supported.
Enable file sharing in Teams chats, including drag-and-drop functionality.
We would appreciate Microsoft's guidance on the supported capabilities, the relationship between B2B Direct Connect and Teams external access domain restrictions, and the exact configuration required to achieve the expected behavior.
Thank you for your assistance.
1 Reply
B2B Direct Connect alone does not replace Microsoft Teams external access configuration. Your requirements can largely be met while keeping users as native accounts in their respective tenants, but chat and file-sharing capabilities depend on the specific Teams collaboration model.
Native accounts, no Guests: You can retain each user's existing home-tenant identity. B2B Direct Connect does not require creating guest accounts for supported scenarios.
Trusted domain recognition: Teams external access domain restrictions are managed separately from Microsoft Entra cross-tenant access settings. Configure the three organizations' domains in the Teams Admin Center allowlist if required by your external access policy.
One-to-one chats: Configure Teams external access and Microsoft Entra cross-tenant settings as appropriate for your intended collaboration model. A B2B Direct Connect relationship alone does not automatically make a domain trusted by Teams.
File sharing and drag-and-drop: Do not assume B2B Direct Connect enables file attachments in every Teams chat scenario. File-sharing support depends on the collaboration type and the applicable Teams and SharePoint/OneDrive policies.
Recommended configuration
Microsoft Entra ID: Configure mutual inbound and outbound B2B Direct Connect access between all three tenants.
Teams Admin Center: Configure external access for the three domains to enable one-to-one chats. The allowlist is managed independently of B2B Direct Connect.
File sharing: Use Teams shared channels with B2B Direct Connect for guest-free collaboration, including channel chat and file sharing. Shared-channel files use SharePoint policies.
SharePoint/OneDrive: Verify the relevant sharing permissions and organizational restrictions.
Important limitation: B2B Direct Connect is currently designed for Teams shared channels; it does not by itself enable guest-free file attachments in standard one-to-one external chats. For one-to-one chat attachments, verify the supported collaboration model before changing policies.
