How to fix authenticator issue?

Question

I was logged out of Authenticator, but when I try to login, it prompts me to use the authenticator app, which I can't do. Not only that but I don't receive requests from Outlook either. I tried to verify using my phone number, but that method isn't available at the time of writing. When I try to login via QR code, it prompts me to use a passkey, when I don't have one. When I try to sign in using my password, it sends an approve sign in request, to the authenticator app (which I still can't use) and I still get nothing from Outlook.

Answer 1

I think ur mfa’s just in that split‑state where the backend still grips a dead device tag, so tap “I can’t use my authenticator” once to force a clean re-reg—if it still loops, only an admin wipe frees u.

Answer 2

Follow these steps in order, based on what is available for the account (work/school vs personal) and what has already been tried:

1. Check for any alternative sign-in methods

• Go to the sign-in page and look for options such as Use a code, Other ways to sign in, I can’t use my authenticator app right now, or SMS/email verification.
• If SMS or backup email is available and working, use that to sign in and then update authentication methods at https://aka.ms/mysecurityinfo (for work/school) or the Security section of the Microsoft account (for personal accounts).

2. If Outlook mobile is configured for the account, try using it as the second factor If the organization allows Outlook as an authentication method and the account is already signed in on Outlook mobile:

• To approve a notification:
  1. Sign in to the target site and choose to send a notification.
  2. When prompted, check the phone and approve the request in Outlook.
• To use a one-time code from Outlook:
  1. Open Outlook mobile and tap the Home icon (top left).
  2. Tap the Settings gear (bottom left).
  3. Under General, tap Accounts, then select the relevant account.
  4. Tap Sign-in requests.
  5. Copy the code and paste it into the sign-in page where Use a code is selected.

3. Fix “Authentication did not complete” / no prompts arriving If prompts are not arriving in Authenticator or Outlook:

• Ensure the app is unlocked when trying to approve.
• Turn on notifications for Authenticator/Outlook and ensure they are not silent.
• Update Authenticator to the latest version using the official download link.
• Ensure the device has a working internet connection; if needed, switch between Wi‑Fi and mobile data.
• Verify the device’s Date & time settings are correct.

4. If the account is a work/school account and no backup method works

• Contact the organization’s IT administrator and request an MFA reset in Microsoft Entra:
  • Admin goes to Microsoft Entra admin center → Users → All users → select the user → Authentication methods → Require re-register multifactor authentication.
  • After this, sign in again and re-register Authenticator or another method.
• If this is the only admin account in the tenant, the Microsoft Data Protection team must be involved:
  • Call the regional Microsoft Support number from Customer service phone numbers - Microsoft Support.
  • Clearly state that this is an Office 365/Entra work account, that it is an administrator account, and that there are no other admins, and request a Data Protection case to reset MFA.
  • If direct access to support is not possible, create a temporary trial tenant, go to the new tenant’s admin center, and open a support ticket asking the Data Protection team to help recover the original tenant admin account.

5. If the account is a personal Microsoft account and no method works

• Use the password reset / account recovery flow via the Reset your password link and follow the prompts to verify identity with any available backup methods.
• If recovery still fails, continue using the official recovery flow; forum moderators and tools outside support cannot override this.

6. If a passkey is requested but not available

• If a message indicates the passkey is invalid or cannot be used, remove any obsolete passkeys from the authenticator app and account security settings, then set up a new passkey.
• After creating a new passkey, retry sign-in using that passkey or reconfigure Authenticator/Outlook as the primary method.

These steps cover: using Outlook mobile as an alternative factor, fixing missing notifications, resetting MFA for work/school accounts via an admin, involving Microsoft Data Protection when the only admin is locked out, and handling invalid or missing passkeys.

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References:

• Using Outlook mobile to sign in
• Sign in using Microsoft Authenticator
• Troubleshoot problems with Microsoft Authenticator
• Authentication did not complete
• Troubleshoot signing in with a passkey
• I have a Micrsoft business account and I am the admin and the only user registered under this account. I can't log in because i have replaced my phone and the authenticator doesn't work. - Microsoft Q&A
• Microsoft authenticator sending me into a spiral - Microsoft Q&A
• Reset Personal Azure MFA - Microsoft Q&A
• Requesting a Tenant Admin MFA Reset - Microsoft Q&A