Three places to put a file, no obvious rule about which, and a quiet consensus in most businesses that it does not matter much. It does — not because of tidiness, but because the wrong choice is what makes documents impossible to find eighteen months later, and what makes a resignation into a data problem.
The good news is that the rule is simpler than the interface suggests.
The underlying thing nobody explains
Teams and SharePoint are not alternatives. Every Team has a SharePoint site behind it, and the Files tab in a Teams channel is a view onto a folder in that site.
When you drop a file into a Teams channel, you are putting it in SharePoint. Teams is the conversation layer; SharePoint is where things are kept. Once that clicks, most of the confusion goes.
OneDrive is the genuinely separate one. It is your personal space, tied to your account — which is the single most important fact about it.
The rule, in one sentence each
OneDrive is for work that is only yours: drafts, notes, the half-finished thing you are not ready to show anyone. If you left tomorrow and nobody would need it, it belongs here.
Teams is for work in progress that a group is actively doing together, where the file and the conversation about it belong side by side.
SharePoint is for work that has settled: the signed contract, the current policy, the reference material people will still need in two years. Structured by subject rather than by who made it.
Where should this actually live?
Five files. Pick where each one belongs.
The mistake that causes the most damage
Using OneDrive as the main store and sharing out of it.
It feels efficient. It works perfectly well. And it makes every document dependent on one person’s account continuing to exist. When they leave, their OneDrive is deleted after a grace period, and everything shared from it stops working — frequently a few months later, long after anyone connects the two events.
If more than one person needs a file regularly, it should not live in OneDrive. That is the whole rule.
The second mistake: a Team for everything
Teams is easy to create, and every one creates a SharePoint site. Left unmanaged, a business of a hundred people accumulates hundreds of Teams, most of them abandoned, all holding data, many owned by people who have left.
A light touch is enough: someone approves new Teams, every Team has two owners, and anything with no activity for a year gets reviewed. It takes minutes and prevents a problem that is genuinely painful to unpick later.
Chat is not storage
Files sent in a one-to-one or group chat go into the sender’s OneDrive, in a folder called Microsoft Teams Chat Files. They inherit all the fragility of OneDrive, and they are invisible to everyone not in that chat.
For a screenshot, fine. For anything that matters, put it in a channel.
A test that settles most arguments
Ask: if the person who created this left tomorrow, would anyone need it?
If no, OneDrive. If yes and it is still being worked on, a Teams channel. If yes and it is finished, SharePoint.
That covers the overwhelming majority of decisions, and it is short enough that people will actually remember it.
If this has already got away from you
It is a common position and not a disaster. The usual approach is to establish the structure you want first, move the things that matter, and let the rest age out — rather than attempting to reorganise everything at once, which reliably stalls.
If you would like a hand working out what that structure should look like for your business, it is a conversation rather than a project.
