Block Other Tenants/Subscriptions

[Jef132]

We are looking into using more of office365 but we have concerns with users being able to login to other office365 tenants from work machines. For example we want the users to be able to login to Our Teams instance but we do not want the users to login to any other random team instances that they may have. How do we stop this? The URL's seem very generic so i can't block all URL's except for our companies URL......how are other companies handling this issue?

[#2 · Accepted solution]

Tenant restrictions is the only such functionality offered: https://docs.microsoft.com/en-us/azure/active-directory/manage-apps/tenant-restrictions

[#3]

This is great thanks for the info. I think this will do what we need.
I was expecting to have to use a CASB to accomplish this.