External identities in Azure: B2B collaboration and B2C customer sign-in
Slide deck explaining external identities in Azure: Business-to-Business (B2B) collaboration for partner access and Business-to-Customer (B2C) customer sign-in for customer-facing applications.
External identities in Azure: B2B collaboration and B2C customer sign-in
Introduction to external identities in Azure: Business-to-Business (B2B) collaboration and Business-to-Customer (B2C) customer sign-in.
External identities in Azure: B2B collaboration and B2C customer sign-in
Introduction to external identities in Azure: Business-to-Business (B2B) collaboration and Business-to-Customer (B2C) customer sign-in.
External identities: what & why
Let outside users sign in without creating employee-style internal accounts. External users equals outside your organization. Avoid employee-style account lifecycle work (onboarding/offboarding, password resets). Still enforce access control and review. Microsoft Entra ID (formerly Azure Active Directory (Azure AD)) plus External ID.
Workforce tenant vs external tenant
Match the tenant setup to the user type: employees vs customers. Workforce tenant: employees plus internal resources. External tenant: customer-facing apps plus customer accounts. Choose based on user type and goal. Clear boundaries reduce confusion later.
Business-to-Business (B2B) collaboration
Invite partners as guests and grant access to specific resources. Used for partners, vendors, other organizations. Invite as a guest user. Grant access to specific apps/resources (not default broad access). Guest signs in with an existing identity.
Guest user object ≠ guest password
Your tenant stores a guest record for access decisions, while sign-in usually uses an existing identity. Tenant stores a guest user object for access decisions. Used for groups, roles, and policies. Credentials usually remain with the guest's identity provider. You control permissions and sign-in rules.
Business-to-Customer (B2C) and CIAM
Customers sign in to your app, with customer accounts managed for that app's needs. B2C: customer-facing applications. Customer Identity and Access Management (CIAM) focus. Sign-up and sign-in at large scale. Customer accounts managed in an external tenant.
Older vs newer naming you may see
Azure AD B2C appears in older docs; External ID is the newer CIAM approach. Azure Active Directory (Azure AD) B2C: older/legacy CIAM references. Microsoft Entra External ID: modern CIAM approach in current docs. Goal stays the same: customer sign-in for your app. Focus on the scenario, not the label.
Rule of thumb: B2B vs B2C/CIAM
Use user type and goal: partners access your resources (B2B), customers sign in to your app (B2C/CIAM). B2B: partners/guests accessing your organization's resources (workforce tenant). B2C/CIAM: customers signing in to your application (external tenant). User type plus goal equals your decision shortcut. Keep access scoped and intentional in both models.
External access still needs controls
External identities reduce admin work, but security and reviews remain essential. Least privilege access control (grant only what's needed). Conditional Access (CA): sign-in rules and protections. Multi-Factor Authentication (MFA): stronger sign-in when appropriate. Governance: regular access reviews to prevent stale access.
Practical: vendor access with their work account (B2B)
If a partner uses their own work identity to access your internal resource, think B2B collaboration. Invite vendor users as guest users. Grant access to one app/resource (scope tightly). Don't manage vendor passwords as employee accounts. Use groups/roles and policies for control.
Practical: customers signing in to your app (B2C/CIAM)
If users create accounts to sign in to your public app, think B2C/CIAM. External tenant holds customer accounts for the app. App supports sign-up and sign-in. Consumer sign-in options (email, social identity providers). Built for large numbers of users.
Common pitfalls + 3-step checklist
Avoid confusion and stale access by always scoping, protecting, and reviewing external access. Don't treat external users as default employees. Don't confuse B2B (partner access) with B2C/CIAM (customer sign-in). Don't skip security controls for external users. Checklist: Scope → Policy → Review.