Multi-Factor Authentication (MFA) is a great security tool, and we always recommend it. Office 365 admins can enforce MFA for users, which means you can help protect anyone sharing your Office 365 business subscription.
To do this you’ll need to be an Office 365 administrator, which only happens with a business plan. If your Office 365 subscription comes as part of a domain hosting package, then you’ll have access to the Admin console. However, if you’ve just purchased a personal subscription (or home subscription for your family), then you won’t have access to the Admin console, and you can only turn MFA on for yourself. If you’re not sure, click the Office 365 app launcher and look for the Admin tile.
If it’s there, you’ve got access to the Admin console. Click the Admin tile, and on the menu on the left-hand side click Settings > Services and add-ins.
This opens the Services and add-ins page, where you can make various tenant-level changes. One of the top items will be “Azure multi-factor authentication.”
Click this, and on the panel that opens on the right, click “Manage multi-factor authentication.”
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Source : How to Enforce Multi-Factor Authentication for All Users of Your Office 365 Subscription
