Azure AD B2C vs External ID

Question

I’m trying to find answers regarding the transition from Azure AD B2C to Microsoft Entra External ID, and it would be great if someone could shed some light on this, especially considering the recent announcement that new Azure AD B2C tenants will no longer be created after May 1, 2025.

1. Advantages, Disadvantages, and Limitations of Microsoft Entra External ID vs. Azure AD B2C
   • Can you point me to a detailed comparison table outlining the advantages, disadvantages, and key limitations of Microsoft Entra External ID versus Azure AD B2C? For example,

Azure Ad B2cExternal IdCustom PolicyNot supportedWhat is the alternative to support all scenarios of custom policyMFA Using Authenticator App?1. Federation with Other Identity Providers and Custom Logic Support

• Will Microsoft Entra External ID support federation with other identity providers using both SAML2 and OIDC protocols?
• What is the level of support for custom logic and complex workflows currently implemented in Azure AD B2C custom policies? Will organizations be able to replicate these advanced scenarios seamlessly in Microsoft Entra External ID?

1. Service Availability by Region
   • Could you provide a list of regions where Microsoft Entra External ID is currently available?
   • For organizations operating in regions where Microsoft Entra External ID is not yet supported, what alternative solutions does Microsoft recommend after May 1, 2025, when the creation of new Azure AD B2C tenants is no longer allowed?
2. Migration Path from Azure AD B2C to Microsoft Entra External ID
   • Is there currently a defined and automated migration path for transitioning from Azure AD B2C to Microsoft Entra External ID?
   • If not, when can we expect such a migration solution to be available?
   • What best practices or phased strategies do you recommend for organizations planning to migrate while maintaining business continuity?
3. Impact on Business Models Requiring New B2C Tenants
   • In some scenario, a business might create a new Azure AD B2C tenant for each client's use. However, with the announcement that new B2C tenants cannot be created after May 1, 2025, this could pose a significant operational concern for clients who rely on this model

Answer 1

Hi @Learner-6009

Thank you for posting this in the Microsoft Q&A forum.

To clarify, Azure AD B2C will continue to be supported until at least May 2030 for existing customers. However, starting May 1, 2025, new customers will no longer be able to purchase Azure AD External Identities P1 and P2. Existing Azure AD B2C tenants will remain fully operational, including the ability to create new tenants or user flows.

Comparison: Azure AD B2C vs. Microsoft Entra External ID (CIAM)

Feature	Azure AD B2C	Microsoft Entra External ID (CIAM)
Custom Policies	Supports complex XML-based custom policies	Not supported, but designed to handle equivalent use cases with simpler configurations
User Flows	Available	Available, with improved experience
UI Customization	Full control over HTML and CSS	Limited to branding and styling options
Identity Provider Federation	Supports OIDC & SAML	Supports OIDC, SAML, WS-Fed, and social logins (Google, Facebook, Apple, etc.)
Security & Compliance	Standard security policies	Enhanced security with risk-based authentication & adaptive access
Developer Experience	XML-based configurations	More intuitive and low-code/no-code approach

For more information Supported features in Microsoft Entra External ID

Microsoft Entra External ID supports federation with other identity providers using SAML2, OIDC, and WS-Fed protocols.

Regarding custom logic and complex workflows, custom policies are not supported in Microsoft Entra External ID. However, the platform is designed to offer equivalent capabilities through built-in user flows, API connectors, and extensibility options.

Microsoft Entra External ID is a customer identity and access management (CIAM) solution that stores and manages data in a separate tenant created for your customer-facing apps and customer directory data. This tenant is called the external tenant. When you create an external tenant, you have the option to select the geographic location for data storage.

Currently, there is no automated migration process publicly available. The migration solution is under testing and will be released for public preview in the future.

For updates on its availability, please follow: Microsoft Entra External ID: What's New.

For organizations that currently create a new Azure AD B2C tenant for each client, the inability to create new tenants after May 1, 2025, may impact operations. Businesses that heavily depend on creating new B2C tenants for each client may need to reevaluate their operational processes and business models. They might need to consider alternative approaches or solutions to accommodate this change. You can consider alternative approach as Microsoft Entra External ID if strict tenant separation is required.

Hope this helps. Do let us know if you any further queries.

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