Receiving Authenticator notifications that says “New sign in request for your Microsoft account.

Those unexpected Microsoft Authenticator notifications mean that either someone is trying to sign in to the account, or a sign-in attempt was made with an email/phone similar to the account and the prompt is being sent by mistake.

Do not approve any sign-in requests that were not initiated intentionally. Approving a request would grant access to the account.

Recommended actions:

1. Deny every unrequested prompt
   When the notification appears, always choose Deny if the sign-in was not initiated.
2. Review recent account activity
   Go to the account’s recent activity page and check for unfamiliar sign-ins or security events. If anything looks suspicious, use the option there to secure the account.
3. Strengthen sign-in security
   Consider moving to passwordless sign-in methods such as Microsoft Authenticator number matching, Windows Hello, SMS/Email codes, or physical security keys. These methods are designed to be more secure and reduce the risk from password guessing or phishing.
4. Use Authenticator/Outlook correctly when signing in
   When intentionally signing in, always verify the number shown on the sign-in screen and tap the matching number in Authenticator (or Outlook mobile, if enabled) before approving. This helps prevent accidental approval of a malicious prompt.

If unrequested prompts continue after securing the account and changing the password, keep denying them and periodically review recent activity to ensure no unauthorized access is occurring.

References:

• Troubleshoot Microsoft verification code issues
• Sign in using Microsoft Authenticator
• Using Outlook mobile to sign in