Glossary
Cross-Tenant Access Settings
Microsoft Entra ID configuration for trust between Microsoft 365 tenants — B2B, shared channels, multi-tenant collaboration.
Cross-Tenant Access Settings (CTAS) in Microsoft Entra ID govern the trust relationship between your tenant and other Microsoft 365 tenants — for B2B collaboration, Teams shared channels, Multi-Tenant Organisations, and cross-tenant synchronization. Configured in the Entra admin center → External Identities → Cross-tenant access settings. Includes inbound controls (which external tenants' users can be invited or trusted with shared resources, with what conditions) and outbound controls (how your users can collaborate externally). Granular per-tenant trust lets you require external MFA / compliant device for some partners while blocking others entirely. The modern surface for designing partner-collaboration architecture.