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By , IT support technician

Quick Answer

Download the Microsoft Authenticator app from your phone's app store. Go to mysignins.microsoft.com/security-info on your computer, click Add sign-in method, select Authenticator app, and scan the QR code with your phone.

How to Use the Microsoft Authenticator App ​

Applies to: Microsoft 365 (iOS, Android)
Article Type: How-To
Last Updated: 2026-03-09

Summary ​

The Microsoft Authenticator app is used to approve multi-factor authentication (MFA) prompts and can enable passwordless sign-in for your Microsoft 365 account. This article covers installing the app, approving sign-in requests, and setting up passwordless access.

Prerequisites ​

  • A smartphone (iOS or Android).
  • A Microsoft 365 account with MFA enabled by your organization.

Instructions ​

1. Install the Authenticator App ​

Download and set up the app on your phone.

  1. Open the App Store (iOS) or Google Play Store (Android).
  2. Search for Microsoft Authenticator and install the official app by Microsoft Corporation.
  3. Open the app and sign in with your Microsoft 365 work account email address.
  4. Follow the prompts to complete setup. Your organization may require you to scan a QR code — this is typically provided during your initial MFA enrollment.

2. Approve a Sign-In Request ​

Respond to push notifications when signing in.

  1. Sign in to a Microsoft 365 service (Outlook, Teams, etc.) with your email and password.
  2. A notification appears on your phone: "Approve sign-in?"
  3. Open the notification. You may see a number matching prompt — a two-digit number on your computer screen that make sure you match in the app.
  4. Tap the matching number on your phone, or tap Approve.
  5. You are signed in on your computer.

Tip: If you do not have cellular service, the Authenticator app can still generate time-based one-time passcodes (TOTP). Tap your account in the app to see a 6-digit code that refreshes every 30 seconds. Enter this code when prompted instead of using the push notification.

3. Set Up Passwordless Sign-In ​

Skip your password entirely and use the app to sign in.

  1. Open the Authenticator app on your phone.
  2. Tap your work account.
  3. Tap Enable phone sign-in (or Set up phone sign-in).
  4. Follow the prompts to register your device.
  5. The next time you sign in to Microsoft 365:
    • Enter your email address (no password).
    • A number appears on screen.
    • Open the Authenticator app, tap the matching number, and verify with your fingerprint, face, or PIN.
  6. You are signed in without typing a password.

4. View and Manage Accounts ​

Check or remove accounts from the app.

  1. Open the Authenticator app.
  2. Your accounts are listed on the main screen. Tap an account to see:
    • The current one-time passcode (refreshes every 30 seconds).
    • Account details and settings.
  3. To remove an account, tap the account > tap the gear icon or three-dot menu > Remove account.

Troubleshooting ​

DANGER

If you lose your phone or get a new one, you will need to re-register the Authenticator app. See the related article below for transferring MFA to a new device. Without a registered device, contact your IT helpdesk for a temporary bypass.

Symptom / ErrorPotential CauseSolution
Not receiving push notificationsNotifications blocked on phoneCheck your phone's notification settings and ensure Authenticator notifications are allowed.
Number matching prompt not appearingApp or OS out of dateUpdate the Authenticator app and your phone's operating system to the latest version.
"Account already exists" errorDuplicate registrationRemove the existing account from the app, then re-add it by scanning a new QR code from your security settings.