Originally published at: http://www.howtogeek.com/173339/dont-get-locked-out-when-using-two-factor-authentication-5-recovery-methods-to-set-up/
Two-factor authentication secures your accounts with an additional authentication method, often a time-limited code generated by a mobile app. But what happens if you lose or reset your phone and can’t generate the codes?
Can I recommend Authy?
It's an alternative for Google Authenticator which I use, since it allows automatic backups and recovery.
They even have a blogpost describing their security of the backup system:
Can anyone tell me what happens when I get a new iPhone to the codes in the GAuth app? When I boot up the new phone I would restore from a back up in iCloud. Does this preserve the codes? If not then that would mean everytime I upgrade my phone I would need to disable two factor authentication on for each service and then re-enable it? Or am I missing something obvious?