In this article I’ll show two ways to find out your Office 365 TenantID using the Portal and using PowerShell.
Once you are ready, Open PowerShell or ISE and type the cmdlet below:
Your tenant ID Is 32 alpha numeric code found In next to the AcountObjectID
If you don’t want to use PowerShell, you could do it using the GUI however it’s a bit tricky.
To use the Portal, open the Portal and click on Azure AD under Admin center
After clicking on the link watch the address bar In the browser and copy the 32 digit number as seen below next to the arrow.