When litigation or investigations loom, every organization has the same responsibility: preserve the relevant evidence. That's what legal holds are for. But these days, the evidence you need isn't just sitting in email archives anymore. It's often in Slack threads, DMs, emojis, and GIFs. And when Legal needs that data, it's usually IT who gets the request to retain and preserve it.

Slack doesn't give you tools to manage this out of the box however, making it tricky to pull defensible evidence out of it. This guide explains how legal holds work in Slack, why they matter, and how to manage them without endless headaches.

"Since launching to the public in 2013, Slack has made everyone's work life easier and more productive. Except for legal professionals handling ediscovery."
-Everlaw

What is a legal hold?

A legal hold (sometimes called a litigation hold or preservation order) is a formal instruction to preserve data that may be relevant to a pending or anticipated legal matter.

That data can include both paper records and electronically stored information (ESI): emails, chat logs, attachments, databases, and yes — Slack conversations.

When & why legal holds are triggered

Legal holds are issued when litigation or an investigation is reasonably anticipated. Common Slack-related scenarios include:

• HR investigations: harassment or discrimination claims involving Slack DMs or private channels.
• Financial services: compliance reviews where Slack records contain client communications.
  
• Healthcare: instances of PHI being shared on Slack
• IP disputes: product ideas or code snippets shared in Slack threads.

Sometimes Legal drives the hold (responding to outside counsel or a regulator). Other times HR triggers it internally. In both cases, IT gets the call to preserve Slack data before anything is lost.

When You Receive a Subpoena

If your organization receives a subpoena, litigation hold notice, or court order demanding Slack data, you must immediately place a legal hold to preserve all potentially responsive data. Failure to preserve data after receiving a subpoena can result in spoliation sanctions, even if you plan to object to the request. The typical response timeline is 30-40 days from receipt to production, and preservation must happen on Day 1. For the complete process including objections, collection methods, review workflows, and costs ($15K-$100K+), see our Slack subpoena response guide.

Challenges unique to Slack

Slack adds a layer of complexity that email and file servers never had:

• Ephemeral messages: edited or deleted threads.
• Reactions and media: emoji reactions, GIFs, and threaded replies may be contextually important.
• Retention limits: Free plan users only get 90 days of message history.
• Exports aren't simple: IT can't just click "Export" and hand over defensible evidence.

These challenges explain why many IT teams dread the phrase: "Can you pull this Slack data for Legal?"

Here's how Slack is different from traditional formats:

Risks of non-compliance in Slack

Failing to preserve Slack data can lead to spoliation — loss or alteration of evidence. Courts take this seriously.

• Under FRCP Rule 37(e), sanctions may include adverse jury instructions, dismissal, or monetary penalties.
• In practice: if key Slack conversations "disappear," your case can suffer even if the deletion was unintentional.

The bottom line: treating Slack as an informal channel won't cut it in court.

Does Slack Have a Legal Hold Feature?

Short answer: Yes, but only on Enterprise Grid.

Slack introduced a native legal hold feature for Enterprise Grid organizations that allows admins with the "Legal Holds Admin" role to preserve messages and files from specific custodians.

What Slack's legal hold feature does:
✅ Preserves messages and files from designated members
✅ Overrides workspace retention settings (data won't be deleted)
✅ Protects content even if users edit or delete messages
✅ Supports up to 1,000 custodians per hold
✅ Allows scoping by conversation type (all conversations vs. DMs only)
✅ Accessible via JSON export or Discovery API

Critical limitations:
❌ Slack Connect conversations are NOT preserved (huge gap for external communications)
❌ Emoji reactions are NOT included (problematic for regulated industries)
❌ Messages in deleted channels are NOT saved (must preserve channels separately)
❌ Only available on Enterprise Grid (Free, Pro, Business+ plans have no legal hold capability)

If you're on Enterprise Grid, Slack's legal hold feature is a good foundation, but you still need to manually track and document holds (Slack doesn't provide custodian notification workflows). And preserve Slack Connect channels and emoji reactions separately (major oversight in Slack's feature). You also have to prevent channel deletion during the hold period.

If you're on Free, Pro, or Business+ then you have no native legal hold option. You'll need to rely entirely on manual exports and third-party preservation tools.

How technology helps

Many organizations still track legal holds with spreadsheets and email reminders. That's a recipe for missed custodians and inconsistent documentation.

Modern tools made for legal teams make the process smooth:

• Issue hold notices electronically
• Create and manage template hold notices
• Track acknowledgments automatically
• Preserve Slack data without manual CSV wrangling
• Generate reports for auditors or regulators

ViewExport on the other hand is a Slack eDiscovery tool designed specifically for parsing and searching Slack exports. Instead of IT spending weeks searching, marking, and editing JSON files, you get a searchable, export-ready workspace for compliance.

Slack legal hold process at a bird's eye view

1. Trigger event: A demand letter arrives, or HR flags an investigation. From that point forward, the duty to preserve kicks in.
2. Identify custodians: Custodians aren't just email inboxes anymore. In Slack, custodians may be people (employees, contractors) but also channels (project workspaces, DMs, private groups).
3. Draft and distribute the notice: Legal sends notices to custodians explaining their duty not to delete or alter information.
4. Preserve the data: Here's where Slack gets tricky.
   • Free & Pro plans: only public channels are exportable, with a 90-day history cap on Free, making the free plan a non-starter for most organizations
   • Business+: more export options, but private messages and DMs often require Slack approval.
   • Enterprise Grid: built-in legal hold feature, with limitations: putting a hold can't prevent the deletion of entire channels, emoji reactions aren't included, and Slack Connect isn't covered
   Tools like ViewExport fill this gap — letting IT teams quickly capture and search Slack exports in a way Legal can actually use.
5. Monitor and document compliance: Custodians acknowledge holds; IT documents every action (which user accounts were put on hold, when retention settings were changed, etc, in case of later scrutiny.)
6. Release the hold: When the case or investigation closes, custodians and IT are notified that they can return to normal retention schedules.

Okay, now let's go through that in detail...

Refresher: How To Export Data From Slack

Here's a step-by-step guide to manually exporting Slack data for legal holds, summarizing this fuller article here.

Step 1: Access Slack Admin Settings

1. Log in to your Slack workspace as an Owner or Admin
2. Click your workspace name (top-left) → Settings & administration → Workspace settings
3. In your browser, navigate to https://[your-workspace].slack.com/admin
4. In the admin panel, go to Settings → Import/Export Data
5. Click Export tab

Step 2: Choose Export Type

Slack offers different export options depending on your plan:

If you're on Free/Pro: You'll only get public channel messages. This is insufficient for most legal holds.

If you're on Business+/Enterprise Grid: You can request broader exports, but may need to notify users or get consent for private channel access (check your jurisdiction's privacy laws).

Step 3: Set Date Range and Submit

Specify the date range matching your legal hold preservation period. If the case is ongoing, you'll need to re-export periodically to capture new messages in scope. Next, click "Start Export" and Slack will process the request (timeframe varies based on data volume). Then they email you with a download link when ready.

Timeline expectations:
- Small workspaces (<1,000 messages): 5-10 minutes
- Medium workspaces (10,000-100,000 messages): 30-60 minutes
- Large Enterprise Grid workspaces: Several hours to days

Step 4: Download and Review the Export File

1. Click the download link (expires after 7 days)
2. Extract the .zip file
3. Inside, you'll find:
- JSON files for each channel (one file per channel, per day)
- users.json — list of workspace members
- channels.json — metadata about channels
- (Usually) a files folder with attachments

What the Export File Looks Like

Here's a preview of the JSON structure you'll encounter:

 [
   {
     "type": "message",
     "user": "U123ABC",
     "text": "Can we approve the Q4 budget today?",
     "ts": "1609459200.000500",
     "thread_ts": "1609459200.000500",
     "reply_count": 3,
     "reactions": [
       {
         "name": "thumbsup",
         "users": ["U456DEF"],
         "count": 1
       }
     ]
   }
 ]

Key fields:
- user: Slack user ID (cross-reference with users.json to get real names)
- text: Message content
- ts: Timestamp (Unix epoch format)
- thread_ts: If present, indicates this is part of a thread
- reactions: Emoji reactions (may or may not be included depending on export settings)

Step 5: Convert JSON to Human-Readable Format

Raw JSON files are not suitable for attorney review. You'll need to:

- Option A: Import into an eDiscovery platform such as Relativity, Everlaw, Disco, or other - although even this does not guarantee you'll be able to run advanced searches
- Option B: Use a Slack export viewer tool like ViewExport (that's us)

That's pretty much it.

Slack Features That Complicate Legal Holds

Slack Canvas: Collaborative Docs That May Contain Evidence

Slack Canvas is Slack's built-in collaborative document feature. Unlike traditional messages, Canvases are living documents that multiple users can edit simultaneously, and they're problematic for legal holds.

First, their version history is limited because Slack doesn't preserve every edit like Google Docs does. They're also not included in standard exports, and many IT teams discover too latemust be manually preserved

Best practice is to Identify all Canvases in relevant channels before initiating holds. Screenshot or PDF export each Canvas with visible timestamps and contributor lists.

Huddles: Audio Conversations and Transcript Preservation

Slack Huddles are audio (and sometimes video) conversations that happen directly in channels. The legal hold question: are these recorded? By default, Huddles are NOT recorded automatically. If recording was indeed enabled, Files dosave to the channel, but... (a) Not all users know recording is available; (b) Recordings can be deleted by admins; and (c) Transcripts (if auto-generated) may not be preserved in exports.

So, the risk is: Critical conversations happen in Huddles without any record. For litigation, this creates a "he said, she said" scenario.

To counter this, IT should:
1. Audit workspace settings to see if Huddle recording is enabled
2. Check if any recordings exist in custodian channels
3. Preserve both audio files AND auto-generated transcripts
4. Document in the hold notice that Huddle recordings (if any) are in scope

Workflow Builder: Automated Messages That Might Be Relevant

Workflow Builder can automate routine messages like onboarding notifications, approval requests, weekly reminders. These automated messages appear in channels like regular messages. So, they might contain compliance-relevant content (e.g., "Expense report approved by @manager").

They can also be deleted if retention policies aren't configured properly. A common oversight is that IT teams preserve user-generated messages but forget that workflow-triggered messages are equally discoverable.

Shared Channels: Who Has Preservation Responsibility?

Slack Connect (formerly called "Shared Channels") lets your organization message external partners. This creates a jurisdictional headache, say if your company is on legal hold and you have a shared channel with a partner or vendor (or four). Who preserves the messages?

While you obviously must preserve your own org's messages, AND those of the other parties in the shared channel that are relevant to the case, the technical reality is that you can only export what's visible in your workspace.
This means you must (a) Identify all Slack Connect channels involving custodians, (b) Issue preservation notices to external organizations if needed, (c) Export shared channel data from your workspace, and (d) Document any limitations (e.g., "Vendor X controls their message retention; we exported what was visible as of [date]").

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Quick Reference: Legal Hold Checklist for Slack Data

When a legal hold is triggered, here's your Slack-specific checklist:

• Confirm trigger event and scope
• Identify relevant channels, users, and custodians
• Pause auto-deletion or retention limits
• Export relevant Slack data (public, private, DMs if approved)
• Store in a searchable, secure system (e.g., ViewExport)
• Distribute hold notices and track acknowledgments
• Monitor compliance and update as needed
• Release hold when the matter concludes

You can also make a copy of the Google Sheets version of that checklist, by clicking this link. Then, for every matter, just create a new tab and check off as you go.

P.S. If you'd like a short version of this to save to your desktop, we have that for you: