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Microsoft 365 Application

Microsoft Authenticator

Use this guide when you need help setting up Microsoft Authenticator on a phone for work sign-in approvals, number matching, and multi-factor prompts.

Reviewed April 2026

Application Guide

Overview

Microsoft Authenticator is the mobile app many organizations use for multi-factor sign-in approvals and number matching.

Most setup problems come from setting up the wrong account, not finishing the QR-code or code-based enrollment, or moving to a new phone without adding the work account again.

Plain English

What this app is usually used for

Mobile multi-factor authentication app used for Microsoft sign-ins, number matching, approval prompts, and work account setup.

It is part of the Microsoft 365 family covered in our app help.

Common problems

Common problems

The work account will not add to Authenticator

Authenticator opens, but the setup code or QR code does not finish adding the account.

Likely fix

Start the setup again from the company or Microsoft prompt and confirm you are adding the correct work account.

What to collect

Send a screenshot of the setup step that fails and the work account you are trying to add.

Approval prompts are not arriving on the phone

You try to sign in, but the phone never shows the approval request.

Likely fix

Check Authenticator notifications, make sure the phone is online, and open the app to see whether the request is waiting inside the app.

What to collect

Send the phone type, whether notifications are enabled, and a screenshot of the Authenticator account screen.

You changed phones and sign-in no longer works

The old phone had Authenticator working, but the new phone does not approve sign-ins yet.

Likely fix

Add the work account to the new phone and confirm it can receive prompts before removing the old phone from your normal sign-in process.

What to collect

Send the phone type, whether you still have the old phone, and a screenshot of the account list in Authenticator.

First things to try

First things to try

Quick checks before you change anything

  • Are you setting up Authenticator for the first time, replacing an old phone, or trying to approve a sign-in that is not reaching the app?
  • Is the issue adding the account, getting approval prompts, or approving the correct sign-in request?
  • Do you still have the old phone, or is the new phone the only device you can use?

Try these fixes first

  • If you are replacing a phone, do not remove the old Authenticator setup until the new phone is working if the old phone is still available.
  • Check that the phone has notifications enabled for Microsoft Authenticator.
  • If no approval prompt arrives, confirm you are signing into the correct work account and that the phone has internet access.
  • If a number-matching screen appears, compare the number on the phone to the one shown on the sign-in page.

Slow down

Do not do this yet / warnings

Avoid these until support says it is safe

  • Collect exact error wording, organization, affected apps, web-versus-desktop behavior, and recent password, multi-factor sign-in, or device changes before Tier 2 takes over.
  • Do not reset OneDrive or recreate Outlook profiles until permissions, licensing, and organization selection are confirmed.
  • Do not remove Microsoft Authenticator until you confirm you have another approved sign-in method or the new phone is already set up.

What support needs

What details support needs

Send these details

  • A screenshot of the exact Authenticator setup or approval screen.
  • The work account you are adding or approving.
  • The phone type and whether it is iPhone or Android.
  • A note about whether you are setting up a first phone or replacing an old phone.

Licensing & access

Licensing / access notes

Licensing / access checks

  • Use the exact work account your company expects for Microsoft 365 or company sign-in.
  • Authenticator itself is a sign-in method, so the key detail is which work account is being added and whether your organization already expects that account to use Authenticator.
  • If you use more than one Microsoft account, confirm you are adding the work account and not a personal account.

Phone / Tablet

Phone / tablet setup

  • Install Microsoft Authenticator on the phone you plan to keep using and add your work or school account by scanning the QR code when your company setup page shows it.
  • Allow camera access so the app can scan the QR code and allow notifications if your company uses push approvals.
  • If you changed phones, keep the old-phone status clear because support may need to know whether approval prompts are still landing there.
  • Add a backup sign-in method if your company offers one so you are not locked out if you lose the phone.

More checks

More setup checks

Install / update basics

  • Install Microsoft Authenticator from the App Store or Google Play.
  • Choose Add account, then follow the company or Microsoft setup steps to scan a QR code or enter a setup code.
  • Allow notifications so approval prompts can appear on the phone during sign-in.