An initial (global) default policy is provided and you may also define localised policies targeting specific external tenants.

Note that this feature does not apply to non-Azure AD organisations. These will continue to utilise the pre-existing External Collaboration Settings.

Inbound

To restrict access for Guest users in your tenant.

External Users and Groups

External Users And Groups

Applications

Applications

Trust Settings

Trust Settings

Outbound

To restrict access for your member users in other tenants.

Users and Groups

Users and Groups

External Applications

External Applications