How to Add an Additional Multi-Factor Authentication (MFA) Factor to Your Microsoft 365 Account

Multi-Factor Authentication (MFA) is an essential security measure that adds an extra layer of protection to your Microsoft 365 account. If you want to strengthen your account security by adding an additional MFA factor (such as a phone number, an authenticator app, or a security key), follow this step-by-step guide.

Steps to Add an Additional MFA Factor in Microsoft 365

Step 1: Sign In to Your Microsoft 365 Account

Open your browser and go to the Microsoft 365 My Account page.
Sign in with your Microsoft 365 credentials (email and password).

Step 2: Navigate to Security Info

Once you're signed in, click on Security Info from the left-hand menu. This will take you to the MFA settings page where you can manage your authentication methods.
- Alternatively, you can directly access your Microsoft Security Info page.

Step 3: Add a New MFA Method

Under Security Info, click on the + Add sign-in method button.
A pop-up will appear where you can select the type of authentication method you want to add.

Step 4: Choose Your Additional MFA Method

Here are the options you can choose from:

Authenticator App: This uses an app like Microsoft Authenticator to generate a code for logging in.
1. Select Authenticator App and click Add.
2. Follow the on-screen prompts to install the Microsoft Authenticator app on your phone (if you haven’t already).
3. Scan the QR code displayed on your screen with the app, then enter the verification code from the app to complete the setup.
4. Download the app here: Microsoft Authenticator App for iOS | Microsoft Authenticator App for Android.
Phone (Text or Call): This option allows you to receive a text message or call with a code.
1. Select Phone and click Add.
2. Choose whether you want to receive a Text message or Call.
3. Enter your phone number and follow the prompts to verify the phone number.
Security Key: This uses a physical USB or NFC security key to authenticate.
1. Select Security Key and click Add.
2. Follow the on-screen instructions to set up your USB or NFC security key.
Email: Note: Whilst Microsoft allows email address to be added, they cannot be used as an additional factor.
1. Select Email and click Add.
2. Enter your email address, and Microsoft will send you a code to verify the email.

Step 5: Verify and Save

After adding your chosen method, you’ll be prompted to verify it by entering a code sent to your phone, email, or authenticator app, or by using the security key.
Once verified, the new MFA factor will be added to your account.

Step 6: Test Your MFA Setup

Sign out and then sign back into your Microsoft 365 account to test the new MFA method.
Microsoft will prompt you to use one of your MFA factors to verify your identity. Make sure the new method works correctly.

Managing Your MFA Methods

You can return to the Security Info page at any time to:

Edit an existing MFA factor.
Remove an outdated factor.
Add new methods to ensure you always have multiple ways to authenticate.

Additional Resources

Microsoft’s MFA Help Center: Microsoft Multi-Factor Authentication Overview
Get the Microsoft Authenticator App:
- Microsoft Authenticator App for iOS
- Microsoft Authenticator App for Android

By following these steps, you'll have an additional MFA factor set up on your Microsoft 365 account, boosting your account's security and making it harder for unauthorised users to gain access.