Tom moved to another state and his Gmail account has been locked out. How can he get back control of it? Google says he has to go back to the old location to recover it. This is why you use an alternate address for recovery. But if that doesn't work, you may be out of luck since there's no support. Leo says before anything happens, to do the security checkup. Turn on 2-factor authentication, and set up a secondary email that isn't Gmail for recovering it. Also, periodically, back up your email through Google Takeout.
google account recovery
John can't find his phone, and he can't see it through Google's location service. He also can't get into his account because he's lost the recovery codes. Leo also recommends going to the Google "I'm Having Trouble Logging in Page" and answer all the challenge questions. Then he'll be able to recover his account and get a new code.