If your organization has customized the Microsoft Entra ID sign-in page using custom CSS, it’s time to review those configurations.
๐ ๐ซ๐จ๐ฆ ๐๐๐ญ๐จ๐๐๐ซ ๐๐, ๐๐๐๐, ๐๐ง๐ญ๐ซ๐ ๐ฐ๐ข๐ฅ๐ฅ ๐ง๐จ ๐ฅ๐จ๐ง๐ ๐๐ซ ๐ฌ๐ฎ๐ฉ๐ฉ๐จ๐ซ๐ญ ๐ฌ๐๐ฏ๐๐ซ๐๐ฅ ๐๐๐ ๐ฉ๐จ๐ฌ๐ข๐ญ๐ข๐จ๐ง๐ข๐ง๐ ๐ฉ๐ซ๐จ๐ฉ๐๐ซ๐ญ๐ข๐๐ฌ ๐ฎ๐ฌ๐๐ ๐ข๐ง ๐๐จ๐ฆ๐ฉ๐๐ง๐ฒ ๐๐ซ๐๐ง๐๐ข๐ง๐ . ๐๐ก๐ ๐ซ๐จ๐ฅ๐ฅ๐จ๐ฎ๐ญ ๐ฐ๐ข๐ฅ๐ฅ ๐๐จ๐ง๐๐ฅ๐ฎ๐๐ ๐๐ฒ ๐ฅ๐๐ญ๐ ๐๐จ๐ฏ๐๐ฆ๐๐๐ซ ๐๐๐๐.
The affected properties include position (and related properties like top, left, and z-index), margin, transform, opacity, overflow, filter, and others. If your branding relies on these properties to control the placement or appearance of elements, expect changes once support is removed.
๐๐ปYour logos, images, and text will continue to appear, but they may revert to their default placement.
๐๐ปThe major thing is that there is also no replacement or migration path for these retired properties!
๐๐ปThis change only affects organizations currently using custom CSS for company branding. New Microsoft Entra tenants created after January 5, 2026 can’t use custom CSS for branding, and Entra External ID tenants aren’t affected.
The rationale aligns with Microsoft’s Secure Future Initiative (SFI). Fine-grained CSS positioning can be misused to create deceptive sign-in page layouts that closely resemble legitimate branded experiences. Removing support for these positioning properties helps strengthen phishing resistance while preserving core branding capabilities.
Before the deadline, I recommend taking time to:
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Pull your current branding configuration through Graph Explorer and review every branding localization for deprecated CSS properties.
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Remove any dependencies on the retired properties and redesign the branding where necessary.
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Validate the sign-in experience after the changes to ensure the layout still appears as expected.
The long rollout window gives admins enough runway to prepare, and it’s a reasonable moment to simplify branding customizations while aligning with where Microsoft is heading on phishing-resistant sign-in experiences.
About the retired CSS properties and Microsoft’s recommendations in the official documentation.
https://lnkd.in/eTq6brfZ