Bad Request when logging on to Office 365

Tags: office 365, outlook, exchange, email, errors

At times you may receive a "Bad Request" error when logging on to Office 365 or Exchange email. This issue is usually due to you or a previous user not having logged out correctly. This may be with your work or school account, but also a Microsoft account such as, or

To prevent this issue from happening, always make sure that you log out correctly when closing your browser:

  1. Click the account button in the top right corner of the screen (an outline of a person or the image you may have selected)
  2. Select "Sign Out"

Of course, if you share your computer with other people, it is even more important to sign out correctly before leaving the computer unattended.

If you share your computer with other people under the same computer username, even though we strongly recommend against such a scenario, it is also crucially important that you do not check the "keep me signed in" option when you log on.

If you are already receiving the "Bad Request" error, often the simplest solution is to close all browser windows. If this fails to resolve the issue, you can opt to delete your browser cookies as described in the article Clearing your browser cache.

Quick access to support articles


General Support Articles


Product Support Articles


Support Articles with common Fixes


Social Media Support Articles


Technical Support Articles


eCommerce Support Articles