Copilot data loss rules will also cover Microsoft Cowork
Reviewed by Helen Jones
Microsoft is extending Purview Data Loss Prevention (DLP), the company controls that stop sensitive content leaking from apps, to Microsoft Cowork. Message Center item MC1477182, dated 22 September 2026, says existing DLP policies aimed at Microsoft 365 Copilot will apply to Cowork automatically, and new Copilot DLP policies will include Cowork by default. Admins can use sensitivity labels to restrict which labelled sources Cowork can ground on, plus Sensitive Information Types to inspect prompt text and block specified sensitive wording from Bing search. Prompt and web-search DLP cover typed prompt text only at this release, not files users upload. Public preview runs from late September into early October 2026. Worldwide general availability is scheduled from mid-October through late October 2026. Microsoft rates admin impact as medium and user impact as low, with no required end-user action.
Until now, Copilot DLP lived in one place while Cowork sat outside that net. Teams could treat Cowork as a separate experiment, or worse, assume Copilot protections already followed every new Microsoft AI surface. That gap made champions hesitate to put real mail and files in front of a tool they could not explain to security. The change is that Copilot and Cowork will share the same DLP policies unless someone opts out of that default. That is useful for labelled knowledge and risky prompt text, but it is not a full file firewall. If your company still has thin Copilot DLP, Cowork inherits the same holes. If policies are already tight, Cowork does not need a second playbook just to stay inside the same rules.
Analysis
This is a watch item for whoever owns Copilot DLP, not a reason to start a Cowork rollout. Ask that admin to confirm existing Copilot DLP policies will inherit, then note in the team playbook that prompt and Bing checks do not cover uploaded files at launch.
Source note
Pulse published by Collab365 Spaces, reviewed by Helen Jones on . Cite as "Copilot data loss rules will also cover Microsoft Cowork", Collab365 Spaces. 2 sources referenced.