How to Set Up Microsoft Authenticator
A plain-English setup guide for iPhone, Android, Windows, and Mac
What Is Microsoft Authenticator and Why Do You Need It?
Microsoft Authenticator is a free app that adds a second layer of security to your Microsoft 365 login. When you sign in, you enter your password as normal — then Microsoft sends a prompt to the app on your phone asking you to approve the login. This means a stolen password alone is not enough to get into your account.
If your business uses Microsoft 365 and your IT provider or admin has asked you to set this up, follow the steps below for your device.
What You Need Before You Start
Your Microsoft 365 credentials
Your work email address and Microsoft 365 password. If you are not sure what these are, ask your IT provider or admin.
A smartphone
The Authenticator app runs on your phone — iPhone or Android. You will use your phone to approve logins from any device.
Access to your current email or phone
During setup, Microsoft will verify your identity by sending a code to your existing email or phone number.
5 minutes
The setup process takes approximately 5 minutes on any device. Follow the steps for your platform below.
iPhone / iOS
iPhone / iOS
Open the App Store on your iPhone and search for Microsoft Authenticator.
Download and install the app — it is free. The icon is a blue padlock.
Open the app and tap Add account.
Select Work or school account.
Select Sign in and enter your Microsoft 365 email address and password.
Microsoft will send a verification code to your email or existing phone number — enter it to confirm.
Your account will appear in the Authenticator app. From now on, when you log in to Microsoft 365 you will be prompted to approve the sign-in in this app.
💡 If your organisation uses QR code setup, select 'Scan a QR code' in Step 4 instead and scan the code shown on your computer screen.
Android
Android
Open the Google Play Store and search for Microsoft Authenticator.
Download and install the app — it is free.
Open the app and tap Add account.
Select Work or school account.
Select Sign in and enter your Microsoft 365 email address and password.
Complete the verification step when prompted.
Your account will appear in the Authenticator app. Future logins will prompt you to approve the sign-in in this app.
💡 The steps are almost identical to iOS. If your IT provider has sent you a setup link, tap it on your Android device and it will open directly in the Authenticator app.
Windows — Setting Up via Browser
On Windows, you set up the Authenticator through your browser at aka.ms/mfasetup. You will need your phone nearby to scan a QR code during setup.
Windows
Open your browser and go to aka.ms/mfasetup and sign in with your Microsoft 365 account.
Click Add sign-in method and select Authenticator app.
Click Download now if prompted — this will direct you to download the app on your phone. If you already have it installed, click Next.
A QR code will appear on screen. On your phone, open the Authenticator app, tap Add account → Work or school account → Scan a QR code, then scan the code.
Microsoft will send a test notification to your phone — approve it to confirm the setup is working.
Click Next and then Done. Your phone is now registered as your second sign-in step.
💡 On Windows, the setup is done through your browser — not a desktop app. The Authenticator app itself runs on your phone, not your PC.
Mac — Setting Up via Browser
On a Mac, the process is the same as Windows — you set up through your browser and your phone does the approvals.
Mac
Open your browser (Safari or Chrome) and go to aka.ms/mfasetup.
Sign in with your Microsoft 365 email and password.
Click Add sign-in method and select Authenticator app.
A QR code will appear on screen. On your phone, open the Authenticator app, tap Add account → Work or school account → Scan a QR code, then scan the code.
Approve the test notification on your phone.
Click Done. Setup is complete.
💡 The process is the same as Windows — the setup happens in your browser and the Authenticator app runs on your phone.
Common Issues
I am not receiving the approval prompt
Check your phone's notification settings for the Authenticator app — notifications must be enabled. Also check you have an internet connection on your phone.
I have a new phone
If you get a new phone, you need to set up the Authenticator app again. Contact your IT provider — they can help reset your MFA registration so you can re-enrol on the new device.
The QR code is not scanning
Make sure your camera has permission to be used by the Authenticator app. Try moving your phone closer or further from the screen, or reduce screen glare.
I am locked out of my account
If you cannot get into your account and cannot approve the MFA prompt, contact your IT provider immediately. They can temporarily reset your MFA so you can log back in.
Need Help Setting This Up?
DM1 can walk you through the setup remotely or onsite. Call (08) 6202 6012 or send us a message.