How to Set Up Microsoft Authenticator Number Matching to Stop MFA Fatigue Attacks on Your Microsoft 365 Account

Summary

This guide helps you troubleshoot and resolve: How to Set Up Microsoft Authenticator Number Matching to Stop MFA Fatigue Attacks on Your Microsoft 365 Account. Follow the steps below to fix the issue.

Common Causes

Number matching is a security feature in Microsoft Authenticator that helps prevent MFA fatigue attacks. Instead of simply tapping "Approve" on a push notification, you must enter a two-digit number displayed on your sign-in screen into the app. This ensures you are actively authorising the login and stops attackers from spamming you with approval requests until you accidentally accept one.

Before You Begin

Number matching is enforced by your organisation's IT administrator. You cannot enable it yourself. If you do not see a number prompt when signing in, your administrator may still be rolling out the feature or your account may not be configured for it yet.

Add Your Account to Microsoft Authenticator

1. Download Microsoft Authenticator from the Apple App Store or Google Play Store.
2. Open the app and tap Add account.
3. Select Work or school account.
4. Use your phone's camera to scan the QR code displayed during your Microsoft 365 sign-in setup, or sign in with your work email and password when prompted.
5. Allow notifications when asked so you can receive sign-in prompts.

Use Number Matching to Sign In

1. Sign in to your Microsoft 365 account on a computer or browser.
2. When prompted, look for the two-digit number shown on your screen.
3. Open the notification on your phone.
4. Enter the matching two-digit number in the Microsoft Authenticator app.
5. Tap Yes to complete the sign-in.

Verify Number Matching is Working

1. Sign out of your Microsoft 365 account on a browser.
2. Sign back in with your email and password.
3. Confirm that a two-digit number appears on your computer screen.
4. Enter the number in the Microsoft Authenticator app on your phone.
5. Tap Yes to approve the sign-in.

Troubleshooting

I am not receiving push notifications

• Check that your phone has an active internet connection (mobile data or Wi-Fi).
• Ensure notifications are enabled for Microsoft Authenticator in your phone settings.
• Disable battery optimisation or low power mode for the Authenticator app on Android devices.

The number on my screen does not match the app

• Make sure you are entering the number shown on the device you are signing into, not a code from another app.
• Refresh the sign-in page and request a new prompt.
• Close and reopen the Microsoft Authenticator app.

I am still being asked for a simple Approve button

• Confirm your organisation has enabled number matching for your account.
• Remove your account from the Authenticator app and re-add it using the steps above.
• If the issue persists, contact your IT support team so they can review your security settings.

Still Having Issues?