We only keep 90 days of chat. Is our data still worth anything?

Often, yes. Published provider thresholds count years in business or of records, and email, tickets, accounting and shared files are kept by default unless someone set them to delete too. On Slack Free, messages 90 days to a year old are hidden, not deleted.

Is our older chat deleted, or just hidden?

That depends on which setting produces the 90 days, and only one of them leaves older messages in place. As of October 2026:

Where the 90 days comes from	What happened to older messages	Source
Slack Free plan’s view limit	Hidden, not deleted, until they are a year old. Slack says “When you upgrade, your messages and files beyond the 90-day limit will be revealed”	Slack
Slack Free retention setting	Deleted. Owners on Free can “either keep all messages and files for one year, or delete them after 90 days”	Slack
A 90-day retention policy on a paid Slack plan	Deleted. “Data deleted according to your retention setting is permanent.”	Slack
A Microsoft Purview policy that deletes Teams messages after 90 days	Deleted from the mailboxes Teams uses for compliance copies and from the chat service itself	Microsoft, updated June 3, 2026
Google Chat auto-deletion	Deleted after the period an admin sets, from 30 to 36,500 days, on Business Plus, Enterprise and some other editions	Google

Slack changed the Free plan’s history rules in 2022 and again in 2024. On September 1, 2022, it replaced the old limit of 10,000 messages and 5 GB of files with 90 days of history, Forbes reported in July 2022. Since August 26, 2024, Slack may delete Free workspaces’ messages and files older than a year “on a rolling basis”. A workspace that has stayed on Free therefore holds about a year at most, and only the last 90 days of it are in view.

Ask whoever administers your chat tool which row applies. The plan is on the billing page, a Slack Workspace Owner can see the retention setting, and a Microsoft 365 administrator can list Purview retention policies.

Can we still get the hidden Slack messages out?

Possibly, on Free. Slack’s export guide says that on the Free plan “Data more than a year old will not be included”, and its export page limits Free exports to file links from the last 90 days; neither page sets a 90-day limit on messages. The standard export covers public channels only. Run one and look at its earliest date before you treat the history as gone.

Upgrading reveals the hidden messages and ends the Free plan’s one-year deletion, because paid plans keep data “for the lifetime of your workspace by default”. It cannot bring back anything already deleted, by the one-year rule or by a retention setting. Whether a few extra months of chat justify a subscription depends on what your other systems hold. The Slack page covers plan history, private channels and exports in full.

Do buyers need years of chat?

No published threshold sets a length for chat history. They count years in business or years of records, as of October 2026:

• Corpus’s checklist asks that a company has been “Operating since 2018 or earlier”, “Uses Slack, Teams, Workspace or Microsoft 365” and has “CRM, ticketing or project history”.
• Handshake AI looks for “20+ full time employees & 3+ years in operation”.
• License My Data’s route for larger companies asks for “100+ employees and four or more years of history, across three or more systems in active use”.
• Miro Advisory looks for “Five or more years of operating history in real systems”.
• Nyne asks for “3+ years of real operational workflows that your teams already run on”.
• Scale AI looks for “Years of records in the tools your teams already run on”, without a number.
• Telegraph Lab, which is affiliated with Data Licensing Report, describes eligible referred companies as having “3+ years of work in their documents, software, and internal records”.

Years still move the numbers. Avelence’s published model outputs give $80,000 to $300,000 for a 20-person US company with one year of records and $160,000 to $500,000 with ten, and Avelence says they “are not buyer offers or annual revenue”. Where a threshold counts years of records (License My Data, Miro Advisory, Nyne and Telegraph Lab), 90 days of chat alone would not meet it, and ten years of email, jobs and invoices beside that chat would meet the year count.

Polyshares’ description of what it licenses shows where chat sits: “The working record of the business. Slack, email, Drive, spreadsheets, CRM history, support tickets, design files, call recordings, accounting and ERP exports.” Short chat retention shortens one line of that list.

Where does the rest of our history usually sit?

In systems that keep records until someone deletes them. Defaults, as of October 2026:

Records	System	Default	What to check
Email and shared files	Google Workspace	“By default, Google Workspace data stays in user accounts until the user or admin deletes it”	The oldest message in two or three long-serving mailboxes
Email	Microsoft 365	Mail stays until a user deletes it, and Microsoft lists no time limit on the Deleted Items folder for any plan (Microsoft)	Whether a retention policy deletes mail, and the oldest message
Support tickets	Zendesk	In most cases Zendesk “automatically archives tickets 120 days after they are closed”, and an admin can set schedules that delete archived tickets	Whether a deletion schedule is switched on
Jobs, invoices and call recordings	ServiceTitan	No time limit in its terms or help articles while you subscribe (checked October 2026)	The oldest job and the oldest recorded call
Accounting	QuickBooks Online	Intuit’s usage limits list no cap on transactions or years of history	The oldest transaction, and any older QuickBooks Desktop file

Some of them can be set to delete, as your chat was, through a Google Vault or Microsoft Purview retention rule or a Zendesk deletion schedule, so check rather than assume.

What should I check?

1. Which chat tool and plan you use, and which row of the first table produces the 90 days.
2. On Slack Free, the earliest date in a public-channel export.
3. The oldest email in two or three long-serving mailboxes, and how many former employees’ mailboxes still exist. Does my company’s data qualify? covers deleted ones.
4. The oldest ticket, job, invoice and accounting transaction.
5. The oldest files on your shared drive. Data Licensing Report’s sample tool counts a folder’s files by type, size and date without opening any of them.
6. Any system you replaced, and where its records went.

Write each date into your data inventory, with chat as one row among the others.

What do I do next?

1. Leave settings as they are while you decide. Don’t shorten retention anywhere else, and don’t move a paid Slack workspace back to Free, which would put anything over a year old under the Free plan’s deletion again. On Free, messages pass the one-year mark every day, so decide early whether the hidden months matter.
2. Ask who set the deletion rule, and why. A client contract, an internal policy or a lawyer’s advice may be behind it, and the same reason may limit what else you can license. Is it legal to sell company emails and records? lists the documents to read.
3. Build the inventory across every system. The years in email, tickets, jobs and accounting are what you describe to a buyer.
4. Apply with that inventory. List the years each system holds, including the short chat history, so providers price what you actually have.