The official line from MS is that you can’t have multiple accounts from the same organisation signed-in to office at the same time. You can’t use the Office account switcher in the top-right. If you try to sign in with another user from your org, you will get the following message:

..and your only option is to sign-out the first user, possibly disconnect the Work or School account. Unfortunately, if the first user is the only one that has a license to activate the office desktop apps, then you probably do not want to sign-out of it.

The trick is usually to add your secondary account into Outlook, and allow Outlook to add it as a Work or School account. This results in both accounts showing up in the Office Account Switcher, and you can click between them, with the apps staying activated, OneDrive / Sharepoint, cloud settings and recent files working properly, even if the secondary account only has a basic license without desktop apps.

I recently had an issue where this didn’t work, and for the life of me I could not get it to work. I could not get the secondary account to add itself in to the account switcher without signing out of the main account first – which de-activates Office. It seems that if you do things in the wrong order, it’s nearly impossible to get it right again. The ability to choose your identity within the same org can be quite important, and not just for activation purposes.

Here are my notes from just now, to save myself the hours of messing next time.

On a new computer or new user profile, it seems that if you start out by adding the fully licensed (Business Standard or Premium) email account to Outlook, and activating the product with the same, then you can add the secondary account to Outlook during the Outlook welcome screen, and both accounts will stay active in the account switcher in all office apps.

If you somehow end up with it not working (e.g., accounts added in wrong order, or main account signed-out), then it’s a nightmare to fix. After much trial and error, this seems to work:

  • Disconnect both work or school accounts
  • Remove outlook profile
  • Delete all of HKCU\Software\Microsoft\Office
  • Delete %localappdata%\Microsoft\OneAuth

Then proceed as per new computer / profile above. The requirement to use Outlook might have something to do with the main email account corresponding to the entry in LicenseIdToEmailMapping

There are many times when it seems that you have it working, but then closing and reopening Word or Excel a couple of times causes the inactive account to be removed, and the apps become deactivated.