Author: Konstantinos Tsoukalas , Last updated: April 9th, 2026
In this guide, you'll learn how to set up multi-factor authentication on your Microsoft account to prevent unauthorized access and secure your personal information and data.
As cyberthreats increase, protecting your online accounts with just a password is no longer enough. Multi-Factor Authentication (MFA) adds an extra layer of security to your Microsoft account by requiring a second verification step—like a code sent to your phone or approval through the Multifactor Authenticator app.
How MFA works:
Multi-Factor Authentication (MFA) is a security system that requires users to verify their identity using one or more methods beyond their password.
When MFA will be required:
You will be prompted to complete MFA whenever any of the following occurs:
- It has been 90 days since the last MFA.
- You sign in from a different device.
- You sign in from a different browser or an incognito window in the same browser.
- You sign in from an unusual or unfamiliar location (for example, another country or region).
- The system detects suspicious or unusual activity on your account.
How to Protect your Microsoft Account via Multifactor Authenticator app.
Step 1. Install Microsoft Authenticator on your Phone Device.
1. On your phone open Google Play Store (Android) or the Apple Store (iOS).
2. In the search, type "Microsoft Authenticator" and then install the Microsoft Authenticator app on your device.
3. When done, proceed to next step.
Step 2. Enable Multifactor Authentication on your Microsoft Account.
1. From your PC, sign in to your Microsoft Account Security Settings using your Microsoft email and password.
2. In the Security info page, click Add sign-in method.
3. On the Add a sign method options, select Microsoft Authenticator.
4. At the "Install Microsoft Authenticator" prompt, click Next.
5. At the "Set up your account in app" prompt, click Next again.
6. Now open the Microsoft Authenticator app on your phone and scan the QR code displayed on your computer's screen. When done, click Next.
7. When you see the "Approve sign in request" prompt, type the number shown on your device's screen (i.e. "86" in this example) into the Authenticator app on your phone, by doing the following:
a. On your phone, tap/open the “Approve sign-in?” notification.*
* Note: If you don't see the notification, open the Microsoft Authenticator app manually and unlock it using your phone’s passcode or Face ID.
b. On the "Are you trying to sign in" window*, type the number shown on your computer screen (i.e. "86" in this example), then tap Yes.
* Note: If you don't see the "Are you trying to sign in" message after opening the Authenticator app, read the instructions in the "Additional help" section below.
c. Now, enter your phone’s passcode or use Face ID to complete the verification. After that, go back to your computer to finish MFA setup. *
* Note: For enhanced security, you can setup a phone number as an additional verification method (SMS text message or phone call). To do this, click Add Sign-in Method in the 'Security info page', choose Phone and add your phone number
What to do if you Receive an MFA Prompt You Did NOT Initiate:
If you receive a prompt to accept a sign-in request on your phone that you did not initiate (i.e. you are not currently trying to sign in to your account), do the following:
1. Tap No, its not me on the "Are you trying to sign in" prompt* on your phone.
2. Login to your Microsoft 365 account, click Security info on the left and change your password immediately.
Additional help:
If you don't see the Sign-request after opening the Authenticator app on your phone, verify that your phone has Internet access and do the following:
1. On your computer, click I can't use my Authenticator app right on your computer and…
2. …select Use a verification code.
3. Then, open the Authenticator app on your phone and tap on your Microsoft account.
4. View your one-time password code and enter it in the "Enter code" window that appears on your computer. When you're done, click Verify to sign in to your account.
That's it! Let me know if this guide has helped you by leaving your comment about your experience. Please like and share this guide to help others.
Frequently Asked Questions
What is Multi-Factor Authentication (MFA)?
Multi-Factor Authentication (MFA) is a security system that requires users to verify their identity using one or more methods beyond just a password.
When will I be prompted for MFA?
You will be prompted to complete MFA if it has been 90 days since your last MFA, if you sign in from a different device, browser, or an incognito window, if you sign in from an unfamiliar location, or if suspicious activity is detected on your account.
How do I install the Microsoft Authenticator app?
Open Google Play Store (Android) or the Apple Store (iOS), search for 'Microsoft Authenticator,' and install the app on your device.
What should I do if I receive an MFA prompt I did not initiate?
Tap 'No, it's not me' on the 'Are you trying to sign in' prompt on your phone. Then, log in to your Microsoft 365 account, click Security info, and change your password immediately.
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Konstantinos is the founder and administrator of Wintips.org. Since 1995 he works and provides IT support as a computer and network expert to individuals and large companies. He is specialized in solving problems related to Windows or other Microsoft products (Windows Server, Office, Microsoft 365, etc.).
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