2.1.2.4. Design for Azure AD B2B and B2C

💡 First Principle: Managing external identities through purpose-built services is essential for enabling secure collaboration with partners (B2B) and providing scalable, customizable identity experiences for consumers (B2C), without compromising the security of the core corporate directory.

Scenario: You are designing the identity solution for a new application. It needs to support external consultants who will access internal Azure resources, and separately, a new customer-facing mobile application that will allow users to sign up and sign in using their social media accounts.

Azure AD B2B and B2C are services within Azure Active Directory (Azure AD) for managing external user identities.

Azure AD B2B (Business-to-Business):

• Purpose: Enable secure collaboration with external partners (e.g., suppliers, customers, vendors) by granting them access to your Azure resources or applications.
• Mechanism: Guest users use their own credentials (Azure AD, Microsoft account, or supported social identities like Google) to access your environment—no need to create separate accounts or manage their passwords.
• Use Cases: Partner collaboration portals, shared document libraries, joint project workspaces, external auditing access.

Azure AD B2C (Business-to-Consumer):

• Purpose: Provide identity and access management for consumer-facing applications at scale (e.g., e-commerce, mobile apps, web portals for end customers).
• Mechanism: Supports local accounts (email/password) and social identity providers (Google, Facebook, Apple, Amazon), with customizable user flows for sign-up, sign-in, and profile management.
• Use Cases: E-commerce sites, mobile apps, web portals for end customers, loyalty programs.

⚠️ Common Pitfall: Using Azure AD B2B for a large-scale consumer application. While technically possible, B2B is not designed for the scale (millions of users) or the customizable user experience (branded sign-up/sign-in pages) that B2C provides.

Key Trade-Offs:

• Collaboration (B2B) vs. Customer Identity Management (B2C): B2B is about inviting known external partners into your tenant as guests. B2C is about allowing unknown consumers to self-register for your application in a separate, dedicated directory.

Practical Implementation: Choosing the Right Service

Reflection Question: How does designing for Azure AD B2B (for partner collaboration) and B2C (for consumer-facing apps) fundamentally enable secure collaboration with external entities and provide customizable identity experiences for consumers, extending Azure AD capabilities to diverse external user types?