Microsoft Teams (free) is accessed through a Microsoft account. If you close that Microsoft account, in addition to not being able to sign in to or access Microsoft Teams (free), you'll no longer be able to sign in to other Microsoft consumer products or services such as Outlook.com, OneDrive, Skype, Xbox Live, or Windows.
Before you close your Microsoft account, you'll want to follow the steps in the How to close your Microsoft account article to make sure you don't leave anything behind. You can also export important Teams data, such as contacts and conversation history.
When you're ready, you can close your Microsoft account by following these steps:
Go to the Microsoft account closure page.
You may be prompted to sign in or verify your password. Make sure you are signed in to the Microsoft account you want to close.
We'll take you through the process to close your account.
Note: For iOS users, you can also start the account closure process from within the Teams app. Tap your profile picture, tap Settings, then scroll down and tap Delete account.
For more help, contact support or ask a question in the Microsoft Teams Community.