SharePoint retention can now archive idle files instead of deleting them

Microsoft Purview Data Lifecycle Management is adding an Archive action to retention policies for SharePoint and OneDrive. Inactive files can move automatically into Microsoft 365 Archive rather than staying in hot storage or being deleted. Public preview was described around September 2026, with general availability from early October into November 2026 (Message Center MC1325441 and MC1472601). The setting is off by default. Existing retention policies do not change until an admin chooses Archive. Archived files stay available for compliance and eDiscovery. AdminDroid and Smikar report they are excluded from Microsoft 365 Copilot indexing. This is file-level archive, not the same as archiving an entire site. Reports put archived storage at about 75 percent less than active SharePoint storage, and Microsoft 365 Archive must already be set up with billing enabled. Processing can take days. Restores from cold storage may take at least 24 hours after a short quick-restore window.
Until now, a retention policy on SharePoint and OneDrive was a keep-or-delete decision. Idle project files either sat in expensive, searchable libraries or vanished on a schedule. Copilot then treated whatever remained in those libraries as fair game, which made stale content feel riskier than it used to. The new action splits the problem. Cold files can leave Copilot’s index and drop storage cost without a deletion fight with project owners. It does not fix Teams sprawl, broken inheritance, or guest links. It also does not run on demand, and a restore is slow enough that users will still file tickets if you archive the wrong library.
Analysis
Treat this as a Copilot and storage control, not a governance programme. Confirm Microsoft 365 Archive billing is on, then apply Archive on one retention policy covering a single unused document library and time a restore with whoever owns legal holds before you touch production sites.
Source note
Pulse published by Collab365 Spaces, reviewed by Helen Jones on . Cite as "SharePoint retention can now archive idle files instead of deleting them", Collab365 Spaces. 3 sources referenced.