How to: Reauthenticate the Microsoft authentication app
To follow this guide, you will need your old phone and your new phone. If you do not have access to either of these, you will not be able to follow this guide. Alternatively, you can reset your Microsoft Authenticator App by contacting support.
In this guide we will cover how you reset your Microsoft Authentication App. This guide would come in handy if you just bought a new phone and need to transfer your Microsoft authentication app to your new device.
If you wish to recover your previous account on a new device, you will need to turn on the backup option on your old phone.
As a first step, you will need to open Microsoft Authenticator, tap the three dots at the top in the right corner, and then tap “Settings.”
Now under the backup section, enable “iCloud Backup” or "Cloud Backup" if you are using Android. This will include backups of your account, usernames, verification codes, and other data.
You will need to install the Microsoft authenticator app on your new phone. You can download it from your phone provider's app store, whether it be Apple’s app store, or Google Play. It is critical that you do not set up any accounts using Microsoft Authenticator, until after you have used the Recovery tool option, since it will overwrite your accounts.
Open the Microsoft authenticator App on your new phone, once the download is finished, and tap “Begin Recovery”. From here you will be asked to sign into your Microsoft account, you will need to use the account you used to back up your old phone. This way your accounts will automatically be added to Microsoft Authenticator on your new phone.
In some cases, you will be prompted to revalidate on your new phone. Revalidation can be performed by scanning a QR code, or by signing into your account.
Note: it is very important that you remember to remove the accounts from your old phone, when you have setup your new phone, and tested that it works.