Slack Message Retention Policies
A message retention policy controls how long Slack keeps messages and files before deleting them automatically. Setting the right retention policy balances two competing needs: keeping useful conversation history accessible while managing data obligations, storage costs, and legal requirements.
Why Retention Policies Matter
REASON TO SET A POLICY EXAMPLE
────────────────────────────── ──────────────────────────────────────
Legal compliance Financial firms must retain records
for 7 years; healthcare for HIPAA
Reduce legal risk Shorter retention reduces the pool
of data that can be subpoenaed
Storage cost control Delete old files to stay within
storage limits on paid plans
Privacy regulations GDPR in Europe requires data
minimization — keep only what's
needed, delete the rest
Security hygiene Old sensitive messages (passwords,
credentials) auto-delete after 30 days
Retention Options Available
RETENTION SETTING WHAT IT DOES
────────────────────── ────────────────────────────────────────────
Keep messages forever Default — nothing ever auto-deleted
Delete after X days Messages older than X days auto-delete
(e.g. 30, 90, 365)
Custom duration Set a specific number of days or months
Per-channel policies Override the workspace default for specific
channels (longer or shorter retention)
How to Set a Workspace-Wide Retention Policy
- Go to workspace name → Settings & administration → Workspace settings.
- Click the "Message retention" tab.
- Choose your policy: keep forever, or delete after a set number of days.
- Apply the same policy or different policies to DMs and channels separately.
- Click Save.
Retention policies only apply to new messages going forward from the moment you save the setting. Messages already older than the threshold are deleted according to your schedule, which Slack processes gradually.
Per-Channel Retention Overrides
You can set a different retention period for specific channels. For example, your workspace default might be 1 year, but the #general-chat channel only needs 30 days while #legal-contracts needs 7 years.
- Open the channel.
- Click the channel name in the header.
- Select "Edit settings".
- Find "Message retention".
- Set a custom duration for this channel.
RETENTION POLICY MAP EXAMPLE WORKSPACE DEFAULT: 1 year # general-chat → 30 days (casual chat, low value) # customer-support → 2 years (support history needed) # legal-contracts → 7 years (compliance requirement) # team-social → 90 days (fun posts, low value) # announcements → Forever (company records)
DM Retention Policies
Workspace admins can also set retention policies for direct messages. On Business+ and Enterprise plans, this includes both regular DMs and multi-person DMs. Members cannot override or opt out of the workspace DM retention policy — it applies uniformly.
What Happens When a Message Is Deleted by Retention
When the retention period expires, Slack permanently deletes the messages. The deletion is not reversible. The messages disappear from the channel history, search results, and exports. Files attached to deleted messages are also removed. Neither admins nor members can recover retention-deleted messages.
RETENTION DELETION FLOW
Message sent: January 1
Retention policy: 90 days
↓
April 1: Message auto-deleted
April 1: Disappears from channel history
April 1: No longer searchable
April 1: Cannot be recovered ❌
Plan Availability
PLAN RETENTION POLICY CONTROL
──────────── ──────────────────────────────────────────────────
Free No retention policy settings
(messages limited to 90 days searchable only)
Pro Workspace-level retention policies
Business+ Per-channel retention + DM retention policies
Enterprise Full retention controls + legal hold features
Legal Hold
Enterprise Grid workspaces support legal holds — a setting that preserves specific messages, files, or channels from deletion even if a retention policy would normally delete them. Legal holds are used when litigation is anticipated and evidence must be preserved. IT or legal teams configure legal holds through the admin console or Slack's discovery API.
Best Practices
PRACTICE REASONING ────────────────────────────────── ────────────────────────────────────── Set a default of 1–2 years Balances utility and storage Set #security / #credentials to Auto-removes exposed credentials 30 days Set compliance channels to Meets legal requirements 7 years Document your policy in a Canvas Team understands what gets deleted Review policies annually Regulations change; needs change
Key Takeaways
- Retention policies auto-delete messages after a set duration to meet compliance and cost goals.
- Set workspace-wide policies from Workspace settings → Message retention.
- Override the default with per-channel retention policies for channels with unique requirements.
- Retention deletions are permanent — messages cannot be recovered once deleted.
- Enterprise plans support legal holds to preserve specific data even when retention policies would delete it.