Why does my account say "Your license has been assigned by your Team Owner"?

If your license was purchased/provided by your employer or a reseller:
You may be on a Teams account if your license was purchased by your employer or a reseller as part of a Team License.

If you're unsure, please check this with your administrator or reseller.

If your license was gifted to you:
Similarly, you may be on a Teams account if your license was purchased by someone who then gifted it to you, in which case it would also be a Team License.