Microsoft Purview · eDiscovery

Custodian

Identify and manage custodians (data owners) for eDiscovery cases and track their data sources.

Scope: Custodian management within assigned eDiscovery cases

Permissions

  • Custodian Management - Add and remove custodians from cases
  • Data Sources - Identify custodian data sources (mailboxes, OneDrive, SharePoint)
  • Custodian Holds - Place custodian communications on hold
  • Acknowledgments - Track custodian acknowledgment of holds
  • Indexing - Manage custodian index and reprocessing

Common use cases

  • Tracking employees involved in litigation
  • Managing data preservation for departing executives
  • Organizing multi-custodian investigations
  • Ensuring all relevant data sources are identified and preserved

Best practices

  • Document justification for each custodian addition
  • Verify all data sources for each custodian
  • Send hold notifications promptly upon custodian addition
  • Track custodian acknowledgments and follow up on non-responses
  • Remove custodians when no longer relevant to reduce scope

Security considerations

  • Custodian identification can reveal investigation subjects
  • Hold notifications alert custodians to investigations
  • Ensure proper communication with legal counsel before adding custodians
  • Maintain confidentiality of custodian lists

Common questions

When should I assign the Custodian role?

Assign Custodian when you need to: Tracking employees involved in litigation; Managing data preservation for departing executives; Organizing multi-custodian investigations; and Ensuring all relevant data sources are identified and preserved. It is part of Microsoft Purview and should be granted as a least-privilege alternative to broader roles like Global Administrator.

What can someone with the Custodian role do?

The Custodian role grants permissions including: Custodian Management - Add and remove custodians from cases; Data Sources - Identify custodian data sources (mailboxes, OneDrive, SharePoint); Custodian Holds - Place custodian communications on hold; Acknowledgments - Track custodian acknowledgment of holds; and Indexing - Manage custodian index and reprocessing. See the Permissions section above for the full list.

What are the security risks of the Custodian role?

Key considerations when assigning Custodian: Custodian identification can reveal investigation subjects; Hold notifications alert custodians to investigations; Ensure proper communication with legal counsel before adding custodians; and Maintain confidentiality of custodian lists. Review the Security considerations section before assignment, and pair with Privileged Identity Management (PIM) for just-in-time access where possible.

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