Charles Lamanna, the Microsoft executive vice president responsible for Copilot, agents and platform, announced the plan on the company’s Copilot blog on 5 November. The change covers the various Copilot experiences, including Copilot Cowork, Lamanna said. Claude models are already used in, for example, Copilot chat, Copilot in Microsoft 365 apps and Copilot Code.

The EU Data Boundary is Microsoft’s own commitment to store and process data for Microsoft 365 and its other online services within EU and EFTA countries. It is included in eligible customers’ contract terms, with no separate set-up or extra charge. Other leading models, including those Microsoft hosts itself, already process data within the boundary.

Claude models are currently outside the boundary

A Microsoft Learn help page says that Claude models in Microsoft services are currently excluded from the boundary and from in-country processing commitments. In EU and EFTA countries and the UK, the models are off by default. Anthropic acts as a Microsoft subprocessor, processing customer data on Microsoft’s behalf, and use is governed by Microsoft’s Product Terms and Data Protection Addendum.

Organisations already using Claude models in Copilot need take no action, Lamanna said: processing will move within the boundary automatically once the change is available. Others can enable the models at any time, but their processing will move within the boundary only later. The blog gives no exact date; Microsoft promises more details closer to the rollout.

Organisations in EU and EFTA countries and the UK that previously enabled Claude models under Anthropic’s own commercial terms must enable them again, the Learn page says.

The announcement leaves out the UK and models with data retention

The blog covers EU and EFTA countries and does not mention the UK. Nor does it say whether the change applies to Anthropic models with Data Retention, such as Claude Fable 5 and Claude Mythos 5. For these models, Anthropic acts as an independent processor under its own terms, and Microsoft’s contract terms do not apply, according to the Learn page. Anthropic stores most inputs and outputs for up to 30 days and may keep content flagged as potential usage policy violations for up to two years. These models must always be enabled separately.

Admins enable the models in the Copilot settings of the Microsoft 365 admin center, under AI providers operating as Microsoft subprocessors, by selecting Anthropic. This requires the AI Administrator or Global Administrator role, and access can be limited to specific users or Entra ID security groups. Full instructions are on the Microsoft Learn page Claude models from Anthropic in Microsoft Online Services.