Multi-Factor Authentication is where a user is required to provide an account password and another form of authentication to sign-in. Office 365 now includes support for Multi-Factor Authentication where the second factor for authentication is a Cell Phone. This session describes how Office 365 customers can take advantage of Multi-Factor Authentication. It covers configuration, enrollment, and usage by users who are enabled for Multi-Factor Authentication. Best practices are included for Administrative accounts and for Office 365 assigned users, in addition to details of sign-in for Office 365 web-based applications and Office rich client applications.