When logging into an Azure tenant you have the option to switch to another directory (if available). Sometimes you have directories connected there that are not relevant anymore (because of testing etc.). To check if you have more organisations connected to your azure login account. Log into Azure with your acccount and click on your name on the top right. It should have the option to switch direcrtory.
Click on this and you should see the subscriptions connected to your account.
So if not needed anymore the question remains is it possible to remove them?
Off course thats possible ;-). The way to do this is a bit odd but it works..
To remove the not needed Azure AD directory log into https://myapps.microsoft.com. After logging on klick on your name and klick on the gear icon.
Pro tip: If you can’t find the gear icon your screen may be to narrow or the portal may have started in the ‘new experience mode’. You can switch back to the old mode by clicking on the link leave new experience in this menu.
In the screen that pops up you can see all organisations that are connected to your account. (sorry pictures in Dutch but you get the idea.
You have to log on to the organisation you want to leave, to leave it. So klick the logon to leave the organisation button. After logging in to the other tenant you get the option to leave the organisation
Click the leave organisation button. You get asked if you are really sure you want to leave.
Click leave (verlaten). After that the next pop up comes up
So you left the Azure AD that’s not needed anymore. It may take a short while for all changes to propegate through the Azure Active Directory and your user account but after a short while you should be rid of the unneeded Azure Active Directory.