How to Set Up Multi-Factor Authentication for Outlook on Mobile Devices
If you’ve been asked to set up MFA for Outlook mobile — or Outlook on your phone has started asking you to verify your identity and you’re not sure what to do next — this guide walks you through it step by step. Multi-factor authentication (MFA) adds a second check when you sign in, so even if someone gets hold of your password, they still can’t access your email.
Before You Start
- You need a Microsoft 365 account. If you’re not sure whether you have one, check with whoever manages IT in your organisation.
- Download the Microsoft Authenticator app on your phone before you begin. It’s free and available on both iOS and Android.
- Your IT administrator may need to have enabled MFA for your account first. If the steps below don’t appear, check with them.
How to Set Up MFA for Outlook Mobile
Step 1 — Install the Microsoft Authenticator app
Step 2 — Trigger the MFA setup prompt
Step 3 — Link the Authenticator app
Step 4 — Complete the test verification
Outlook will now open as normal. Next time you sign in on any device, you’ll get a prompt in the Authenticator app to approve the login.
If you’d prefer to use a text message instead
Some organisations allow a phone number as a backup method. On the Keep your account secure screen, choose I want to set up a different method, then select Phone. Enter your UK mobile number and choose Text me a code. Microsoft will send a six-digit code — enter it to confirm.
Setting Up MFA Through the Microsoft 365 Portal (if Outlook didn’t prompt you)
For further guidance on MFA and account security, Microsoft’s support pages are a reliable reference.
If That Didn’t Work
- The QR code won’t scan: Make sure your camera has permission to be used by the Authenticator app. Go to your phone’s Settings, find Authenticator, and check Camera is set to Allowed.
- The Authenticator notification never arrives: Check your phone’s notification settings for the Authenticator app, and make sure you’re connected to mobile data or Wi-Fi.
- The ‘More information required’ screen never appeared: MFA may not have been switched on for your account yet. Your Microsoft 365 administrator needs to enable it — this is done in the Microsoft Entra admin centre (formerly Azure Active Directory).
If you use Outlook on a shared Mac or Windows machine as well as your phone, our guides on how to add a shared mailbox to Outlook on a Mac and how to add shared calendars to Outlook on Windows may be useful once MFA for Outlook mobile is sorted.
When to Ask Us
If MFA for Outlook mobile is failing across several people in your organisation, or you’re seeing errors that mention conditional access policies or token failures, that points to something that needs fixing at the admin level rather than on individual phones. Computer Care customers can raise a support ticket and we’ll take a look.