Microsoft Authenticator App Not Working: How to Fix It

Few things are more frustrating than being locked out of your work accounts because Microsoft Authenticator has stopped working. You're staring at your phone, the approval notification never arrives, and every account you need is behind a multi-factor authentication wall. Before you panic or call your IT team at 7 AM, there are several reliable fixes you can try right now.

This guide walks through the most common reasons Microsoft Authenticator stops working and provides clear, step-by-step solutions for each scenario. Whether your notifications have gone silent, your verification codes aren't being accepted, or you've just switched to a new phone, we've got you covered.

Why Microsoft Authenticator Stops Working

Microsoft Authenticator can malfunction for several reasons, and understanding the root cause helps you pick the right fix. Here are the most common culprits:

Outdated app version — Running an old version can cause compatibility issues with Microsoft's authentication servers.

Corrupted app cache — Temporary files can build up and interfere with normal operation.

Incorrect date and time settings — Time-based one-time passwords (TOTP) depend on your phone's clock being accurate. Even a two-minute drift can cause codes to fail.

Push notification issues — Background app restrictions, Do Not Disturb mode, or blocked notification permissions can prevent approval prompts from arriving.

Network connectivity problems — The app needs internet access for push notifications and account syncing.

Account registration corruption — Sometimes the account registration within the app becomes corrupted and needs to be re-added.

Fix 1: Force Close and Restart the App

The simplest fix often works. Force closing Microsoft Authenticator clears its active session and can resolve temporary glitches.

On iPhone

Step 1. Swipe up from the bottom of the screen and pause in the middle (or double-press the Home button on older iPhones).

Step 2. Find the Microsoft Authenticator card in the app switcher.

Step 3. Swipe it up to close it completely.

Step 4. Wait 10 seconds, then reopen the app from your home screen.

On Android

Step 1. Open Settings then navigate to Apps (or Apps & notifications).

Step 2. Find and tap Microsoft Authenticator.

Step 3. Tap Force Stop and confirm.

Step 4. Reopen the app and test whether notifications and codes are working.

Fix 2: Check Your Date and Time Settings

This is one of the most overlooked causes of Authenticator failures. Time-based verification codes are generated using your device's clock. If your phone's time is off by even a small margin, the codes it generates won't match what Microsoft's servers expect.

Step 1. Open your phone's Settings.

Step 2. Navigate to General > Date & Time (iPhone) or System > Date & Time (Android).

Step 3. Enable Set Automatically (or Automatic date & time on Android).

Step 4. If it was already enabled, toggle it off, wait five seconds, and toggle it back on to force a time sync.

After correcting the time, open Authenticator and try generating a new code. The issue should be resolved immediately.

Fix 3: Update Microsoft Authenticator

Microsoft regularly pushes updates that fix bugs and improve compatibility. Running an outdated version is a common cause of unexpected behavior.

Step 1. Open the App Store (iPhone) or Google Play Store (Android).

Step 2. Search for Microsoft Authenticator.

Step 3. If an Update button appears, tap it. If you only see Open, your app is already current.

Step 4. After updating, open the app and verify your accounts are still listed and working.

Fix 4: Clear the App Cache (Android Only)

On Android devices, clearing the app cache removes corrupted temporary files without deleting your accounts.

Step 1. Go to Settings > Apps > Microsoft Authenticator.

Step 2. Tap Storage & cache (or just Storage).

Step 3. Tap Clear Cache. Do not tap Clear Data, as this will remove your registered accounts.

Step 4. Reopen the app and test.

Important: On iPhone, there's no direct cache-clearing option. Instead, uninstalling and reinstalling the app achieves the same result, but you'll need to re-add your accounts afterward (see Fix 7).

Fix 5: Check Notification Permissions

If you're not receiving push notifications for sign-in approvals, the problem might be your phone's notification settings rather than the app itself.

On iPhone

Step 1. Open Settings > Notifications.

Step 2. Scroll down and tap Microsoft Authenticator.

Step 3. Make sure Allow Notifications is toggled on.

Step 4. Ensure Lock Screen, Notification Center, and Banners are all checked.

Step 5. Verify that Do Not Disturb and Focus modes are not blocking Authenticator.

On Android

Step 1. Go to Settings > Apps > Microsoft Authenticator > Notifications.

Step 2. Enable Show notifications.

Step 3. Check that Battery Optimization isn't restricting the app: go to Settings > Battery > Battery Optimization and set Authenticator to Don't optimize.

Fix 6: Re-register Your Account in Authenticator

If a specific account's codes aren't working, removing and re-adding the account can fix corrupt registrations.

Step 1. Open Microsoft Authenticator and tap the account that isn't working.

Step 2. Tap the gear icon or Settings for that account.

Step 3. Select Remove account.

Step 4. Log into your account through a web browser at mysignins.microsoft.com.

Step 5. Navigate to Security info and add a new sign-in method.

Step 6. Choose Authenticator app and follow the setup wizard to scan the QR code with your Authenticator app.

Note: You'll need access to another verification method (like a phone number or email) to log in and complete this process. If you're completely locked out, contact your IT administrator for a temporary access pass.

Fix 7: Uninstall and Reinstall the App

When nothing else works, a clean reinstall can resolve deeper issues. Before you do this, make sure you have cloud backup enabled or an alternative way to verify your identity.

Before Uninstalling

Check cloud backup — Open Authenticator > tap your profile icon > look for backup status.

Confirm alternative MFA — Make sure you have an alternative MFA method registered (phone number, email, or security key).

Document your accounts — Write down which accounts are registered in the app.

Steps

Step 1. Delete Microsoft Authenticator from your device.

Step 2. Restart your phone.

Step 3. Reinstall from the App Store or Google Play Store.

Step 4. Open the app and sign in with your Microsoft account.

Step 5. If cloud backup was enabled, your accounts should restore automatically.

Step 6. If not, you'll need to re-add each account manually using the process in Fix 6.

What to Do If You're Completely Locked Out

If Microsoft Authenticator has stopped working and you can't access any of your accounts, here's what to do:

Try your backup verification method. Most Microsoft 365 accounts have a secondary method like a phone number or backup email. Use that to sign in and reconfigure Authenticator.

Contact your IT administrator. If you're in a managed Microsoft 365 environment, your admin can issue a Temporary Access Pass (TAP) that lets you sign in without MFA so you can reconfigure your app.

Use the Microsoft account recovery process. For personal Microsoft accounts, visit account.live.com/acsr to start the recovery process.

Preventing Future Authenticator Issues

Once you've fixed the immediate problem, take these steps to avoid it happening again:

Enable cloud backup. In Authenticator, go to Settings and turn on cloud backup. This ensures your accounts are recoverable if you lose your phone or need to reinstall.

Register multiple MFA methods. Don't rely on Authenticator alone. Add a phone number and consider a hardware security key as backup options.

Keep the app updated. Enable automatic updates for Microsoft Authenticator so you always have the latest bug fixes.

Set automatic date and time. Keep this enabled permanently to prevent time-drift issues with verification codes.

Frequently Asked Questions

Why is my Microsoft Authenticator showing the wrong code?

The most common cause is incorrect date and time settings on your phone. Enable automatic time sync in your device settings. If the time is correct, try removing and re-adding the account in the Authenticator app.

Can I use Microsoft Authenticator on two phones at once?

Yes, but each device needs to be registered separately for each account. Adding Authenticator to a new phone doesn't automatically deactivate it on the old one. However, for the best security practice, use one primary device and keep the other as a backup.

What happens if I lose my phone with Microsoft Authenticator?

If cloud backup is enabled, you can restore your accounts to a new phone. If not, you'll need to use your backup MFA method to sign in and set up Authenticator again. This is why registering multiple verification methods is essential.

Does clearing the cache delete my accounts?

No. Clearing the cache on Android only removes temporary files. Your registered accounts remain intact. However, tapping "Clear Data" instead of "Clear Cache" will remove everything, so be careful.

My Authenticator notifications work on Wi-Fi but not on mobile data. What should I do?

Check that mobile data is enabled for Microsoft Authenticator in your phone settings. On iPhone, go to Settings and scroll to Authenticator to verify cellular data access. On Android, check Settings, then Apps, then Authenticator, then Data Usage.

When to Call in the Professionals

If your Microsoft Authenticator issues are recurring, affecting multiple users in your organization, or you're managing MFA across a team without dedicated IT support, it might be time to bring in a managed IT partner. At Always Beyond, we help Calgary businesses configure and maintain their Microsoft 365 security stack, including MFA, conditional access policies, and identity management, so authentication headaches don't slow your team down.