Microsoft Entra External ID

Entra External ID is Microsoft's unified platform for identities outside your workforce:

• Customer identity (CIAM) in a dedicated external tenant — successor to Azure AD B2C for new deployments.
• Business partner collaboration (B2B) in your workforce tenant — guests, B2B direct connect, cross-tenant access settings.

Both are managed in the same admin surface and use the same Conditional Access engine.

When to use

• Authenticating customers / consumers into your apps with social or email sign-up.
• Replacing Azure AD B2C (Microsoft's stated path for new CIAM deployments).
• Inviting and governing external partners as B2B guests with Conditional Access.
• Configuring cross-tenant access for federated partner organizations.