Anthropic models in Microsoft Copilot move into the EU Data Boundary and will be enabled by default

As recently announced, Microsoft is moving Anthropic model processing in Microsoft Copilot into the EU Data Boundary. An AI administrator should review the setting before 9 December 2026.

The change affects organizations with tenants in the EU and EFTA region.

Timeline

• Starting in December 2026: Processing for Anthropic models in Copilot moves into the EU Data Boundary.
• Wednesday, 9 December 2026:
  • Microsoft enables Anthropic models for tenants with the default configuration.
  • Microsoft retires the option to allow Anthropic models only in Copilot in Microsoft 365 apps.
  • Advanced Anthropic models with Data Retention (such as Claude Fable 5 and Claude Mythos 5) are not affected by this enablement.

How does this affect your organization?

In January 2026, Microsoft enabled Anthropic models by default in tenants outside the EU and EFTA region.

A few days ago, Microsoft announced plans to bring Anthropic models into the EU Data Boundary. This update will also enable the models by default in EU and EFTA tenants unless an AI administrator disables the setting before 9 December 2026.
After the change, users in these tenants can use Anthropic models across Microsoft Copilot experiences and in Microsoft Copilot Studio. After 9 December 2026, admins can still disable Anthropic models at any time.

This change affects three parts:

1. Anthropic subprocessors setting in the Microsoft 365 admin center
   Currently, it’s not enabled by default in EU and EFTA tenants.
   • If no selection is made: Anthropic subprocessor is enabled for all users.
   • If Anthropic subprocessor is explicitly disabled: Your selection is respected.
   • If Anthropic subprocessor is already enabled: User and group assignments do not change. Processing moves into the EU Data Boundary automatically once available.

2. Retirement of Anthropic models only in Copilot in Microsoft 365 apps

Microsoft is removing the option “All users for Microsoft 365 apps only” in the Anthropic subprocessor setting, changing it to “All users”.
The current Anthropic settings will be aligned with the OpenAI selections: All users, No users, or Specific users and groups.

3. Advanced Anthropic models with Data Retention

Advanced Anthropic models with Data Retention (such as Claude Fable 5 and Claude Mythos 5) are not affected. This is a separate setting in the Microsoft 365 admin center. It is off by default, and according to the Microsoft documentation, that has not changed.

Anthropic models with Data Retention are advanced models (such as Claude Fable 5 and Claude Mythos 5) that require data retention by Anthropic. This means data is stored by Anthropic and not subject to your Microsoft Customer Agreement including commitments in the Product Terms and DPA. Anthropic models with Data Retention (such as Fable 5.0) have additional controls in the Microsoft 365 admin center and are off by default for all scenarios, including in regions when different Claude models are on by default in commercial cloud and for which Anthropic is a Microsoft subprocessor.