How to Sign In to Microsoft 365 and Set Up MFA for the First Time

You can sign in to your Microsoft 365 account and enable Multi-Factor Authentication (MFA) in just a few minutes using the Microsoft Authenticator app.

Step 1: Install Microsoft Authenticator on Your Phone

• iOS: Open the App Store and search for Microsoft Authenticator. Install and open the app.
• Android: Open Google Play Store and search for Microsoft Authenticator. Install and open the app.
• Allow notifications in the app settings (recommended).

Step 2: Sign In to Microsoft 365 for the First Time

1. Go to the Microsoft 365 sign-in page: https://portal.office.com .
2. Enter your full Microsoft 365 email address and click Next.
3. Enter your temporary password and click Sign In.
4. If prompted, change your password – and it will need to be secure.

Step 3: Set Up MFA with Microsoft Authenticator

• After signing in, you’ll see a prompt like “More information required” or “Set up your account”.
• Click Next and choose Microsoft Authenticator as your authentication method.
• On your phone, open Microsoft Authenticator and tap + (Add Account) → Work or school account → Scan QR code.
• On your computer, a QR code will appear. Scan it with your phone’s camera.
• Approve the test notification in the Authenticator app to complete setup.

Step 4: Test Your MFA

• Sign out and sign back in.
• You should now be prompted to approve the sign-in on your phone. Approve it to confirm MFA is working.

By following these steps, you’ll have a secure Microsoft 365 account with MFA enabled, protecting your email and other Microsoft services.