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Hello, thank you for reaching out to Microsoft Q&A.

May I please confirm whether you still have an older mobile device with the Outlook app installed? If so, please open the Outlook app on that device and select the two-digit number that appears on your new device.

If you no longer have access to the old device, you will need to sign in to your account using your password or an alternate security contact method, such as your phone number or email address.

Select "I don't have access to my Outlook app" if you don't have your old device with you.

Then, get the verification code through the Alternate security verification methods.

Enter the code to sign in successfully with your account on Outlook on your new device.

The 2-digit number (for example, 68) is shown inside the Outlook mobile app on the phone that is already signed in with the same Microsoft account.

To find and use it:

1. Make sure Outlook is installed and signed in on the mobile device that receives your sign-in notifications.
2. On the new device, when the sign-in screen shows “Check your Outlook app – 68,” leave that screen open.
3. On the mobile device, when the Outlook notification appears, tap it.
4. In the Outlook prompt, tap the number that matches the one shown on the new device (in this case, 68), then tap Approve if asked.

This confirms the sign-in using Outlook mobile as the second factor.

If no notification appears on the phone, open the Outlook app directly and check for a sign-in prompt there, and ensure notifications are enabled for Outlook on the device.

References:

• Using Outlook mobile to sign in