Azure AAD B2C: migrate custom policies and templates to Entra External ID

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Azure AAD B2C: migrate custom policies and templates to Entra External ID

Stefano Sapienti 110

Hi,

we are searching for some hint or documentation about migrating custom policies and html templates from B2C to External ID. It seems that policies has been replaced by "custom authentication extensions" but there's not a replacement for html templates?

We have heavily customised the UI and the registration flows, it does not seems to be replicable in External IDs and the only migration document is about users (and is basically an import via API).

We are missing something?

Every B2C documentation page contains a banner saying that customers can continue using the product at least until 2030 but if features are completely removed we should evaluate alternatives.

Thanks in advance

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Answer 1

Obinna Ejidike 2,865

Hi Stefano Sapienti

Thanks for using the Q&A platform.

Entra External ID does not support B2C style custom policies; only user flows and custom authentication extensions are supported. Unlike B2C, there’s no capability to upload or host custom UI templates. Most customization comes via company branding or authentication extensions, not template overrides.

Kindly find: https://quic.hkg1.meaqua.org/en-us/azure/active-directory-b2c/customize-ui-with-html?pivots=b2c-user-flow

You can use custom authentication extensions, event-driven REST hooks for flows like attribute collection or token issuance. These let you inject logic, but not full UI control.

Also, you can configure company branding, but not complete custom HTML like in B2C. Kindly find additional information:
https://quic.hkg1.meaqua.org/en-us/entra/external-id/customers/concept-custom-extensions
https://quic.hkg1.meaqua.org/en-us/azure/active-directory-b2c/customize-ui?pivots=b2c-user-flow

If the response was helpful, please feel free to mark it as “Accepted Answer” and consider giving it an upvote. This also benefits others in the community.

Regards,

Obinna.

Stefano Sapienti 110 Reputation points

2025-07-14T09:22:37.8633333+00:00

Hi,

thanks for the quick reply. Based on your answer the "migration path" referred here for existing policies won't be released as it would be a redo from scratch, and UI customisation will be limited, am I right?
Obinna Ejidike 2,865 Reputation points

2025-07-14T09:30:01.65+00:00

Hi Stefano,

You're right, and your interpretation is accurate based on the current state of Entra External ID as of July 2025.

This is more of a rebuild than a migration. Microsoft may add more capabilities over time, but for now, feature parity is not available, especially for UI and policy customization.

You can mark it 'Accept Answer' and 'Upvote' if this helped you.
Tony Yip 50 Reputation points

2025-12-12T20:20:36.3566667+00:00

will you add this features to external id? we have the similar situation, asking us to rewrite all custom policies + UI templates is a big project by itself.

From the azure tech video, we are on our own to do user migration already? any help from Microosft? Does Microsoft even produce any migration guide as it promised since last year and still could not find any,.

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Azure AAD B2C: migrate custom policies and templates to Entra External ID

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