How to Check How Much Data You Have in Microsoft Teams

To check how much data your company has in Microsoft Teams, start with the Teams user activity report in the Microsoft 365 admin center. It counts channel messages and chat messages for up to the last 180 days. Then count Teams files in SharePoint and OneDrive, where Teams actually stores them, and work out how far back your history goes.

None of these steps show anyone’s messages. The reports give counts, and they hide user names by default.

Why the size and age of your Teams history matter

Volume and years of history are two of the four things that set the price of a dataset; the other two are data type and current demand (how pricing works). Years of project channels and support conversations make a deeper record than a few months of light chat.

For Teams you need four things: how active (messages per month), how widely (active teams, channels and people), how many files, and how far back your history goes.

Where Teams keeps your data

Teams spreads its data across other Microsoft 365 services:

What	Where it’s stored
Files shared in a channel	The team’s SharePoint site (Microsoft Support)
Files shared in a 1:1 or group chat	The sender’s OneDrive, in Microsoft Teams Chat Files
1:1 and group chat messages	The participants’ mailboxes, for compliance tools (Microsoft Learn)
Standard and shared channel messages	The mailbox of the parent team
Private channel messages	A dedicated mailbox for each private channel

That’s why one report can’t give you everything. Steps 1 and 2 count messages; Step 3 counts files.

Who can run these reports

Microsoft lets several admin roles view usage reports, including Global Administrator, Teams Administrator and Reports Reader (Microsoft Learn). Reports Reader is the safest choice if someone else is running this for you, because it reads reports without changing settings.

Step 1: Count messages with the user activity report

1. Go to the Microsoft 365 admin center.
2. Select Reports. If you don’t see it, select Show all first.
3. Select Usage.
4. Under Reports, select Microsoft Teams, then the User activity tab.
5. Pick the longest period, 180 days.

The report includes these message counts per person (Microsoft Learn):

• Channel messages: messages posted in team channels, including original posts and replies
• Posts and Replies: the same channel activity split into new threads and responses
• Chat messages: messages posted in private chats

Select Export to download a CSV file, then add up each column. Divide by six for a monthly rate.

The counts cover messages sent with Teams’ built-in features. They don’t include posts or replies from apps, or emails sent to a channel.

Step 2: See which teams are active

On the same Microsoft Teams report page, the team activity report shows usage by team, including active users, active channels and messages (Microsoft Learn). Use it to count how many teams carry real conversation, and which ones hold most of it.

The Teams admin center has its own versions of these reports under Analytics & reports > View Reports, for Teams administrators (Microsoft Learn). Either set works for an inventory.

Step 3: Count Teams files in SharePoint and OneDrive

Because channel files live in SharePoint and chat files live in OneDrive, use the SharePoint site usage and OneDrive usage reports in the same Reports > Usage area. Our guide to checking how much data you have in OneDrive and SharePoint walks through both, including how to pick out the sites that belong to Teams.

Step 4: Estimate your full message history

The usage reports stop at 180 days. To estimate how many Teams messages you have in total, and how far back they go, use eDiscovery in the Microsoft Purview portal. You need to be in the eDiscovery Manager role group (Microsoft Learn).

1. Create an eDiscovery case.
2. Add a search. Choose the people or teams to include as data sources.
3. Add the Type condition and choose Instant messages. Microsoft recommends this to capture 1:1, group and channel chats.
4. Add a date range, for example one calendar year at a time.
5. Run the search and review its statistics, which show how many items matched and where.

Repeat with earlier years until the counts drop to zero; that’s where your Teams history starts.

Microsoft’s guide for this search also covers deleting messages. You only need the search and statistics steps. Don’t run anything labelled purge or delete, which permanently removes messages.

eDiscovery is a compliance tool. If your company has a compliance or legal lead, let them know before you run a search.

What to write down

Measure	Where to find it
Channel and chat messages, last 180 days	Reports > Usage > Microsoft Teams > User activity
Number of active teams and channels	Team activity report
Files and storage from Teams channels	SharePoint site usage report
Files and storage from Teams chats	OneDrive usage report
Messages by year, and the year your history starts	Purview eDiscovery search statistics

Rounded numbers are fine. A hypothetical note like “about 25,000 channel messages and 60,000 chat messages a month, 40 active teams, history back to 2019” is all an estimate needs.

What to leave out at this stage

Counting is not sharing. You don’t need to export or read any messages to take this inventory. When a company does decide to sell, it chooses which teams, channels and date ranges to include, and people’s names and contact details are de-identified before any buyer sees the data.

Private chats and channels raise extra questions about employee communications. Our rights check covers what to review, and you should confirm anything you’re unsure about with counsel.

Next steps

• Count your documents in OneDrive and SharePoint.
• Using Slack or Google Workspace too? See Slack and Google Drive.
• List every business tool your company uses with Take inventory, then request an estimate.