Anthropic Claude Sonnet is now available in Microsoft 365 Copilot

Anthropic Claude Sonnet is now available in Microsoft 365 Copilot for licensed users, except in EU/EFTA, UK, government, and sovereign clouds. It can be selected in Copilot Chat, with rollout completing by late March 2026. Admins may need to opt in where Anthropic is off by default.

[Introduction]

We’re expanding model choice in Microsoft 365 Copilot with the addition of Anthropic Claude Sonnet for users with a Microsoft 365 Copilot license. Claude Sonnet is available in Copilot Chat in Frontier, alongside the latest OpenAI models, giving users the flexibility to choose the model best suited for their tasks. This expansion reflects our commitment to delivering the latest AI innovation for work—while maintaining the security, compliance, and privacy standards customers expect from Microsoft.

[When this will happen:]

• Frontier availability: Claude Sonnet is available now in Frontier.
• General availability (web/desktop/macOS/mobile): Rolling out gradually; expected completion late March 2026.

[How this affects your organization:]

Who is affected:

• Users with a Microsoft 365 Copilot license

Who is not affected:

• Tenants in EU/EFTA and the UK
• Government clouds (GCC, GCC High, DoD)
• Sovereign clouds For these tenants, Anthropic models are not available

For these tenants, Anthropic models are not available and no model option will be shown.

What will happen:

• Microsoft 365 Copilot licensed users will be able to select Claude Sonnet as an option in the model selector within Copilot Chat.
• In regions where Anthropic is configured as a subprocessor and is set to Off by default, admins can choose to opt in to make Anthropic models available for their organization.
• Enterprise Data Protection for Microsoft 365 Copilot continues to apply, with no changes to existing protections.
• Anthropic operates as a Microsoft subprocessor under the Microsoft Data Protection Addendum and Product Terms.
• Anthropic models are currently excluded from EU Data Boundary and in‑country processing commitments.

[What you can do to prepare:]

• No action is required. However, it’s recommended that you review internal guidance and communicate to users that availability.
• If your tenant is in a region where Anthropic is Off by default, review the subprocessor setting and opt in if you want Anthropic models available to users. Learn more: Anthropic as a subprocessor for Microsoft Online Services | Microsoft Learn
• Learn more about Anthropic as a Microsoft subprocessor: Anthropic as a subprocessor for Microsoft Online Services