Microsoft 365 Message Center item MC1435782
MC1435782 - Microsoft Entra ID: Retirement of custom CSS positioning properties in custom branding
Microsoft Entra ID will retire support for custom CSS positioning properties in company branding starting October 2026 to enhance security and phishing resistance. Existing users must remove these properties by then, as no migration path exists. Branding elements remain visible but may revert to default placement.
- Message Center ID
- MC1435782
- Category
- plan For Change
- Severity
- normal
- Services
- Microsoft Entra
- Tags
- User impact, Admin impact, Retirement
- Published
- 2026-07-21
- Last updated
- 2026-07-21
- Expires
- 2026-12-20
[What and Why]To align with Microsoft's Secure Future Initiative (SFI) and its focus on identity security and phishing resistance, Microsoft is enhancing Microsoft Entra custom branding to support more secure, reliable, and consistent sign in experiences. Beginning in October 2026, Microsoft Entra ID will retire support for custom CSS positioning properties used in custom branding. Full retirement of all custom CSS is planned for a future date, and additional notice will be provided before that change occurs.This update helps further reduce opportunities for deceptive or misleading sign in page layouts and supports trusted sign in experiences that better protect users from phishing attacks while maintaining brand customization capabilities.General Availability (Worldwide and GCC): Beginning in October 2026 and expected to complete by late November 2026[Impact on Your Organization]Who is affectedAdministrators managing Microsoft Entra ID company brandingOrganizations currently using custom CSS positioning properties in company brandingOrganizations that do not use custom CSS positioning properties as of July 21, 2026, are not affected and will not be able to use these properties going forwardMicrosoft Entra External ID tenants are not affectedPlatforms/ServicesMicrosoft Entra IDCustom branding for sign-in experiences (including company branding and branding themes)Web-based branded sign-in pagesWhat will happenExisting tenants that currently use custom CSS positioning properties can continue using them until October 2026.Beginning on October 26, 2026, the affected positioning properties will no longer be honored and will stop functioning.Branding elements on branded sign-in pages such as logos, images, and text will remain visible but may revert to their default placement and appearance.There is no supported migration path or replacement for the retired positioning properties.Organizations that do not already use custom CSS positioning properties cannot create new dependencies on these properties.New Microsoft Entra ID tenants created after January 5, 2026, do not have custom CSS available for company branding.Microsoft will notify impacted customers directly in advance of the retirement.The following CSS properties are being retired:position (including top, right, bottom, left, and z-index)margin (including margin-top, margin-bottom, margin-left, and margin-right)transformopacityoverflowfilterpointer-eventsclip-pathmix-blend-modetranslate[Action Required/Recommendations]Action is required if your organization uses any of the retired positioning properties listed above.Recommended actions:Review your Microsoft Entra ID company branding configurations before October 26, 2026.Identify any usage of the retired CSS positioning properties.Remove or redesign branding customizations that depend on these properties.Validate your branded sign in experience after changes are made to ensure the layout remains acceptable.Communicate this upcoming change to identity administrators and support teams.To determine whether your tenant is using retired positioning properties:Sign in using a Global Administrator or Branding Administrator account.Use Microsoft Graph Explorer to retrieve your organization branding configuration.Review all configured branding localizations.Identify any references to the retired CSS positioning properties.Remove those properties before October 2026.Learn more: Configure your company branding | Fundamentals | Microsoft Entra | Microsoft LearnCSS template reference guide | Fundamentals | Microsoft Entra | Microsoft LearnCustomize the sign-in experience for your application with branding themes | Fundamentals | Microsoft Entra | Microsoft LearnMicrosoft Entra ID enhances security of branded sign-ins | Microsoft Entra BlogScience Future Initiative (SFI) | Microsoft[Compliance considerations]No compliance considerations identified. Review as appropriate for your organization.