A retail company is launching a new customer-facing e-commerce web portal and mobile application. The company wants consumers to register and sign in using their choice of personal email or social accounts (such as Google, Facebook, or Apple), while presenting a custom-branded user interface during registration and authentication. Which identity service should the company implement to meet these requirements?

Azure AD B2C (Customer Identity and Access Management): ### What Azure AD B2C is **Azure Active Directory B2C (Business-to-Customer)**—part of the Microsoft Entra External ID portfolio—is a customer identity and access management (**CIAM**) solution. It allows organizations to build secure, scalable authentication workflows for customer-facing applications without requiring external consumers to have corporate directory accounts. ### How it meets the requirements - **Social and personal identity integration**: Azure AD B2C enables customers to authenticate using **social identity providers** (such as Google, Facebook, Apple) or local accounts via personal email addresses and one-time passcodes. - **Customizable user experience**: Organizations can tailor the entire registration, sign-in, and profile management user flows with **custom branding**, custom fields, and localized language options. - **Self-service workflows**: It provides built-in self-service account management, allowing consumers to reset passwords, update profiles, and manage multifactor authentication without internal IT help desk intervention. ### Key advantages and capabilities - **Massive scalability**: Built to handle millions of external user accounts and billions of authentications with low latency and high availability. - **Enhanced security controls**: Directly integrates with **Conditional Access** and **Multifactor Authentication (MFA)** to secure high-risk transactions. - **Custom business logic**: Allows developers to integrate external REST APIs via custom authentication extensions to validate data or enrich security tokens. ### Why this is optimal Azure AD B2C is specifically designed for public consumers accessing external applications, cleanly separating consumer accounts from internal corporate enterprise directories.