Microsoft 365 Copilot turns on Claude for UK tenants by default December 9

Microsoft will enable Anthropic’s Claude AI models in Microsoft 365 Copilot by default for all UK business and public-sector tenants on December 9 — unless administrators act to block or restrict it first. The change applies only to managed work accounts: Microsoft 365 Personal and Family plans are not affected, per Notebookcheck’s reporting of Message Center post MC1546435.

No price change, no new subscription tier, no rollout delay, just a policy switch that flips the default from ‘off’ to ‘on’ for UK customers who haven’t manually configured their AI provider settings. It does not apply to EU tenants, where Claude remains off by default and must be explicitly enabled by admins, a restriction tied to Microsoft’s EU Data Boundary commitment.

The UK sits outside that boundary, so Microsoft is removing the exception. That also means the old ‘Copilot-only’ toggle, which let admins permit Claude inside Copilot but block it elsewhere in M365, vanishes entirely on December 9. After that date, UK tenants with no setting selected will get Claude across Copilot, Researcher, Copilot Studio and Power Platform.