How do I preserve a Microsoft Teams channel including chats, posts, and shared files for litigation?

Preserving a Microsoft Teams channel is more complex than archiving a single mailbox, because a “channel” is really several connected data types stored in different places. Treating it as one object risks missing material that is discoverable in litigation.

When the duty to preserve begins

In US federal civil litigation, the obligation to preserve potentially relevant information generally arises when litigation is reasonably anticipated, not when a complaint is filed or discovery is served. Failure to take reasonable steps to preserve electronically stored information (ESI) can carry consequences under the Federal Rules of Civil Procedure. Preservation duties and sanctions standards differ in state courts and other countries, so confirm the rules for your jurisdiction.

Map what a Teams channel actually contains

A single channel typically spans multiple repositories:

• Channel posts and replies — stored as messages in the underlying group mailbox.
• One-to-one and group chats — stored in individual users’ mailboxes, separate from the channel.
• Shared files — stored in the connected SharePoint site or, for chats, in users’ OneDrive.
• Metadata — timestamps, authorship, edits, reactions, and version history that establish authenticity and chronology.

Steps to preserve defensibly

1. Issue a written legal hold to custodians and IT, suspending any routine deletion, retention, or auto-expiry policies that would purge messages or files.
2. Identify all custodians and locations, including former employees and any private chats that reference the matter.
3. Apply a platform-level hold so content is retained even if a user edits or deletes it; rely on administrative preservation rather than asking custodians to self-collect.
4. Preserve associated files in place in the connected SharePoint and OneDrive sites, including version history.
5. Document your process — who was notified, what was held, when, and how — so you can demonstrate reasonable, good-faith steps.

Common pitfalls

Do not assume archiving the channel captures private chats or that exporting messages preserves metadata. Coordinate legal, records/IG, and IT early, and capture content in a form that retains authorship and timestamps.

For broader context on holds, collection, and proportionality, see e-discovery. The Sedona Conference offers widely cited guidance on preserving collaboration and messaging data.