Teams B2B sync on macOS

hi Raf​ what you’re seeing is expected behavior. With classic B2B guest access, OneDrive on macOS cannot sync document libraries from another tenant. The “Sync” button will appear, OneDrive will open… and then nothing happens. That part is not a bug — it’s a limitation.

What works

Users can:

• Switch tenants in Teams
• Access files in SharePoint/Teams via browser
• Edit files online
• Use “Add shortcut to OneDrive”

What does not work (by design)

With regular B2B guest accounts:

• OneDrive on macOS (and Windows) cannot sync external tenant libraries
• Libraries won’t appear in Finder via OneDrive
• No clear error is shown

That part is not supported today for B2B guests.

When DOES cross-tenant sync work?

It works only if you use:

Microsoft Teams Shared Channels (B2B Direct Connect)

This uses Entra ID B2B Direct Connect instead of guest accounts.

With Shared Channels:

• Users stay in their own tenant identity
• Access the other tenant’s Team/Channel & SharePoint library
• OneDrive on macOS CAN sync the library to Finder
• This is fully supported by Microsoft

Regular teams/shared folders will NOT work. Only Shared Channels.

If requirement = “Files from both tenants must show up in Finder via OneDrive”
You must use Shared Channels, not classic B2B guests

If requirement = “Browser access is enough”
B2B guests are fine

If requirement = “Seamless cross-tenant sync & collaboration”
Use B2B Direct Connect + Shared Channels

Recommendation

Configure B2B Direct Connect in Entra ID (both tenants)

Create a Teams Shared Channel

Invite users as members, not guests

Files live in the resource tenant SharePoint

Users click Sync → Works in OneDrive + Finder

This avoids creating guest accounts and allows proper syncing on macOS.

Do I need to create a Shared Team or Shared Channel?

Yes. Specifically a SHARED CHANNEL.

Anything else will continue to fail silently — that’s expected behavior.