Lost phone that has Authenticator app

Signing in to Authenticator on the replacement phone does not by itself transfer every code; restore an existing backup on the same device platform, or re-register each account if no usable backup exists.^1^

Restore an existing backup

A backup made on iPhone can only be restored to iPhone, and an Android backup only to Android.^2^

Android

1. If already signed in to Authenticator, sign out or remove the accounts first.
2. Open Authenticator and select Restore from backup or Begin recovery before signing in normally.
3. Sign in with the same personal Microsoft recovery account used for backup.
4. Open any account marked Action required, then sign in to complete its setup.^3^

iPhone

1. Use the same Apple/iCloud account and confirm that iCloud Drive, iCloud Keychain, and iCloud Backup are enabled.
2. Install and open Authenticator. The backed-up codes and account names should appear.
3. If an existing backup does not appear, uninstall and reinstall Authenticator, then open it again.
4. For entries showing Sign in to restore your account, select Sign in and complete verification.^2^

What is restored depends on the account:

• Microsoft personal or third-party accounts using 30-second codes: eligible codes are restored.
• Passwordless Microsoft sign-in: only the account name is restored; sign in again.
• Work or school accounts: only the account name is restored; the new phone must be registered again.^1^

If there was no backup, or the restore is empty

The codes cannot be copied from a lost phone after the fact. Use the appropriate recovery route:

• Personal Microsoft account: At sign-in, choose another available verification method. After gaining access, remove the old Authenticator registration and add Authenticator again on the new phone.
• Third-party account such as Facebook, Amazon, or another website: use that service’s backup code or account-recovery process. Then disable its old authenticator configuration and scan a new QR code.
• Work or school account: choose Sign in another way and use any previously registered SMS, voice, security key, passkey, or other method. After signing in, open Security info, add Microsoft Authenticator on the new phone, test it, and only then remove the lost phone.^4^

If no alternative method works for a work or school account, contact the organization’s IT administrator or help desk. Ask them to use their approved account-recovery process, reset the old MFA methods, or require MFA re-registration. If the affected account belongs to another organization where access is as a guest, that organization’s administrator must reset its registration.^5^

Secure the lost phone

After confirming that the new sign-in method works:

• Remove the lost device or obsolete Authenticator method from the relevant account security settings.
• Change the account password if the phone may have been accessible to someone else.
• If the phone is managed by an employer, ask IT to lock or wipe it.
• If using the device maker’s remote-erase feature, note that erasure is irreversible and can permanently delete any data that was not backed up.

References

1. Transfer Microsoft Authenticator account entries to a new phone
2. Back up account credentials in Microsoft Authenticator
3. [Android](https://support.microsoft.com/authenticator/restore-account-credentials-from-microsoft-authenticator#what-information-is-restored-in-authenticator)
4. How can I regain access to my account after losing access to Microsoft Authenticator? - Microsoft Q&A
5. I change my phone and have issues with auhtenticator - Microsoft Q&A