What happens if I lose my authenticator app?

You lose the second factor on every account it was protecting at once, which is why the recovery path matters more than the app:

• Recovery codes are the way back - one-time codes issued when you enable multi-factor authentication, which most people never save.
• Some apps offer encrypted backup - worth enabling, and worth knowing whether yours does.
• A second enrolled device - a tablet or a spare phone - removes the single point of failure entirely.

Print the recovery codes for your email and your banking today and keep them somewhere physical.