How do i manage a user that uses 365 Business premium in to unrelated companies

[Niels_635]

Hi all,

I have a new employee that works for another company as well - and he is going to continue doing so. He is there already using Office 365 in the Cloud in the other company.

When he tries to lock on with the user I have created for him in our company he automatically gets the mail account of his other workplace.

What can I do to remedy this situation? 

[#2]

Login to where exactly? If using any of the browser-based apps, have him open a private session.

[#3]

@Niels_635 

I guess the user is accessing the Office 365 services through browser-based apps, that's why when trying to login to another tenant he is getting logged in to the same tenant on which he logged in earlier. Please ask him to use another browser or else open incognito mode and try to log in.