Every company that moves to Microsoft 365 goes through the same moment of confusion. You now have three places that store files, all three sync to the computer, all three keep version history, and all three appear to do the same thing.
The predictable result: everyone picks one on their own. Six months later, the client proposal exists in four versions — one in the OneDrive of whoever wrote it, one attached in a Teams chat, one in a SharePoint library, and one on somebody’s desktop folder. Nobody knows which one is the good one.
The good news is that the rule for deciding is short. The bad news is that almost nobody explains it before the mess forms.
The rule, in one sentence
OneDrive is your desk drawer. SharePoint is the company filing cabinet. Teams is the meeting table.
You keep drafts in the drawer, official documents in the filing cabinet, and at the meeting table you talk about the documents — you do not store them there.
If you stop reading here, you already have 80% of the value. But the part that settles arguments is understanding what sits underneath.
The technical detail that changes everything
Here is the fact that clears up 90% of the confusion: Teams has no storage of its own.
When you create a team in Teams, Microsoft quietly creates a SharePoint site behind it. Every file you upload to a channel goes into a folder inside that site — the documentation calls this how SharePoint and OneDrive interact with Teams.
And when you send a file in a private chat, it does not go to SharePoint. It is uploaded to your OneDrive, into a folder called “Microsoft Teams Chat Files”, and what the other person receives is an access permission.
The two consequences of this are serious and invisible:
First: an important file sent in a chat lives in one person’s OneDrive. If that person leaves the company and the license is removed, their OneDrive is deleted — and the file goes with it. There is no such thing as a “Teams file”. There is a file belonging to Anna that Anna shared.
Second: there is no conflict between SharePoint and Teams, because they are the same thing. Asking “should I store this in Teams or in SharePoint?” is like asking whether you should keep your money in the bank or in your account.
Where to put each thing
OneDrive: what is yours and only yours
- drafts nobody needs to see yet;
- personal work documents — your notes, your own tracking spreadsheet;
- temporary files, downloads, the PDF you need for the next two days.
The test: if you left the company tomorrow, would anyone need this file? If yes, it is in the wrong place.
You can share from OneDrive, and sometimes that is the right call — sending a spreadsheet to a colleague for review. The problem is using OneDrive as a team repository. At that point you have created a single point of failure with a first and last name.
SharePoint: what belongs to the company
- contracts, proposals, signed documents;
- policies, procedures, manuals;
- marketing material, templates, brand assets;
- anything that has to keep existing after the person who created it leaves;
- anything more than one person needs to find without asking anybody.
The test: if the person who created this file were on holiday, could someone find it on their own? If the answer is “only by asking her”, it is in the wrong place.
Organize by function, not by person and not by year. A “Contracts” library, a “Sales” library, a “Finance” library — with coherent permissions. Microsoft has a guide to planning sites and permissions that is worth reading before you create the first site, because undoing a bad structure later is far more work than getting it right at the start.
Teams: where you talk about the files
Teams is the conversation layer. The file lives in SharePoint; Teams is where you say “look at clause 4, that needs to change”.
Use it like this:
- upload the file to the channel’s Files tab when the work belongs to that team — it goes into the team’s SharePoint site, which is exactly where it should be;
- pin the SharePoint library as a tab when the document belongs to another department. The team reaches it from inside Teams without duplicating anything;
- do not use private chat to deliver a final document. Send the link, not the file. Whoever gets a link always sees the current version; whoever gets an attachment sees yesterday’s.
Sending an attachment in 2026 is sending a photograph of the document. Sending a link is sending the document.
The four mistakes we find in almost every company
1. The owner’s OneDrive has become the company server. This is the most common mistake and the most dangerous. Everything is there, everything is shared from there, and business continuity depends on one personal account. Migrating that to SharePoint later is work, but it is work you will end up doing at a bad moment if you do not do it at a good one.
2. One Teams team per topic. Forty teams, each with its own SharePoint site, and nobody can find anything. A Teams team is for a group of people who work together on a recurring basis. A topic is a channel inside the team.
3. Syncing enormous libraries. The “Sync” button is tempting, but syncing a library with 300,000 items degrades the computer. For large libraries, use “Add shortcut to OneDrive” and turn on Files On-Demand. It is worth knowing the sync limits Microsoft documents before you blame the internet connection.
4. Permissions set file by file. If you are adjusting permissions one file at a time, the structure is wrong. Permissions belong at the library or site level. Individual exceptions are the first thing nobody remembers to review, and that is how the salary spreadsheet ends up visible.
The ten-second card
When in doubt, three questions:
- Does more than one person need to find this on their own? → SharePoint.
- Does this need to survive the departure of whoever created it? → SharePoint.
- Neither of those? → OneDrive.
And Teams? Teams is where you talk about what is in SharePoint. It is never the final destination of anything.
If the mess has already formed
Do not try to fix everything at once — that is the temptation that kills the project in week three.
The approach that works:
- Decide the structure before you move a single file. Which sites, which libraries, who gets access to what.
- Start with the department that suffers most. It is usually sales or finance, and the immediate relief wins over everyone else.
- Move what is alive, archive the rest. Nobody needs the 2019 quotes in the new structure. A “Historical archive” library handles it.
- Agree on the rule and write it somewhere everyone reads. Structure without an agreement reverts to chaos within four months.
This is one of the jobs we do most, and what determines the outcome is never the technical part — it is deciding the structure together with the people who use it, before touching anything. If you are at that point, it is worth a conversation before you start dragging folders around.