# Microsoft Copilot and Claude in the UK explained: the December 9 default, the two Anthropic settings, and where your data goes > Source: > Published: 2026-11-10 15:26:52+00:00 # Microsoft Copilot and Claude in the UK explained: the December 9 default, the two Anthropic settings, and where your data goes The Register reports that UK Copilot tenants get Claude switched on from December 9 unless an admin chooses. Microsoft's own page still lists the UK default as off. We read both, separate the two Anthropic settings, and give the admin path. **This explains reporting by** [The Register: Microsoft is giving Claude the keys to UK Copilot tenants by default (November 10, 2026)](https://www.theregister.com/ai-and-ml/2026/11/10/microsoft-is-giving-claude-the-keys-to-uk-copilot-tenants-by-default/5308693). Read the original first: [https://www.theregister.com/ai-and-ml/2026/11/10/microsoft-is-giving-claude-the-keys-to-uk-copilot-tenants-by-default/5308693](https://www.theregister.com/ai-and-ml/2026/11/10/microsoft-is-giving-claude-the-keys-to-uk-copilot-tenants-by-default/5308693) ## In one minute - The Register reports that from December 9, UK Copilot tenants whose admins have not chosen a setting will have Claude enabled, and that leaving it alone counts as opting in. - Microsoft's page (last updated November 4) says Claude is on by default for most commercial customers, 'excluding EU/EFTA and UK', where the setting shows 'No users'. It does not mention December 9. - There are two settings. Claude as a Microsoft subprocessor falls under Microsoft's Product Terms and DPA. 'Anthropic models with Data Retention', such as Fable 5 and Mythos 5, are off for every tenant until an admin opts in, and Anthropic keeps most inputs and outputs up to 30 days. - Microsoft says Claude models in Copilot are excluded from the EU Data Boundary, and The Register says Anthropic processes the data in the US. UK admins should record a choice before December 9. ## What was reported On November 10 The Register reported that Microsoft will turn on Claude access for UK Copilot tenants from December 9 for any tenant whose admin has not already chosen. In its words, 'leaving the setting untouched means opting in.' It also says Microsoft is retiring the setting that restricts Claude access to Microsoft 365 alone. Microsoft's documentation page for the setting, last updated November 4, does not mention December 9. It says the opposite of a change for now: in the EU, EFTA and UK, 'the AI providers operating as Microsoft subprocessors setting for Claude models appears but the default is set to No users.' The Register does not say where the date comes from, and the page may simply not be updated yet. Plan for the date either way. ## Two settings, two sets of terms The first setting is 'AI providers operating as Microsoft subprocessors'. With it on, Claude models appear in Microsoft Copilot, Researcher, Copilot Studio, Power Platform and Copilot in Microsoft 365 apps. Anthropic works as Microsoft's subprocessor, and Microsoft says its Product Terms and Data Protection Addendum apply. Microsoft also says these Claude models are 'currently excluded from the EU Data Boundary, and when applicable, in-country processing commitments'. The second is 'Anthropic models with Data Retention'. Microsoft names Claude Fable 5 and Claude Mythos 5 as examples. These are off by default for every tenant, everywhere, and no user gets them until an admin opts in and accepts Anthropic's own commercial terms and DPA. Anthropic then acts as an independent processor, and per Microsoft's page stores most inputs and outputs for up to 30 days, flagged content for up to two years, and safety classification scores for up to seven years. The December 9 change, as reported, is about the first setting only. Nothing we read says the data retention models turn on by themselves. ## Why a UK admin should care UK tenants are not inside Microsoft's EU Data Boundary, and The Register says Anthropic processes the data in the US. For a firm with a data residency promise to its own clients, a default that flips on is a change it has to record, even if the answer is yes. For MSPs the work is multiplied. Each UK client tenant needs its own decision, made by someone with the AI Administrator or Global Administrator role. ## Where the setting lives Per Microsoft's page: Microsoft 365 admin center, then Copilot, then Settings, then 'AI providers operating as Microsoft subprocessors'. To turn Claude on, select Anthropic under available subprocessors, save, then choose which users or groups get access. In regions where it is on by default, the page offers 'Disable Anthropic as a Microsoft subprocessor'. Access can be limited to named users or Entra ID security groups, and Microsoft says that assignment applies across Copilot and Copilot Studio. A pilot group is a middle path between all and nobody. ## Who is affected | Case | Status | |---|---| | UK commercial Copilot tenants with no choice recorded | Claude switched on from December 9, per The Register. Not yet on Microsoft's page. | | EU and EFTA tenants | Default stays 'No users', per Microsoft's page. The Register's report covers the UK only. | | Anthropic models with Data Retention (Fable 5, Mythos 5) | Off for every tenant until an admin opts in, per Microsoft. | | GCC High, DoD and sovereign clouds | Claude not available, per Microsoft. | ## What to do - For each UK tenant, open Copilot settings and record an explicit choice before December 9. - If you allow Claude, limit it to a pilot group first. - Leave 'Anthropic models with Data Retention' off unless the client accepts Anthropic's terms and retention. ## What is still unknown - December 9 comes from The Register; Microsoft's page does not show it yet. - Whether setting 'No users' on purpose counts as a recorded choice that survives the change is not stated. - Which Claude models the default covers is not stated in the report. ## Sources - [The Register: Microsoft is giving Claude the keys to UK Copilot tenants by default (November 10, 2026)](https://www.theregister.com/ai-and-ml/2026/11/10/microsoft-is-giving-claude-the-keys-to-uk-copilot-tenants-by-default/5308693) — the original report - [Microsoft Learn: Connect to AI subprocessors (last updated November 4, 2026)](https://learn.microsoft.com/en-us/copilot/implement/connect-to-ai-subprocessor) [AI News Report](https://theainewsreport.com/)· every headline, every morning.