How to Handle Phone Numbers and 2FA While Traveling
Move off SMS before you leave. Authenticator, hardware keys, and a number you still control.
[ journal ]
The lockout happened at a kitchen table, not an airport. A bank still wanted an SMS to a Louisiana number I had already treated carelessly. The eSIM in the other tray could browse the web and could not open the account. Authenticator apps are boring until they are the only door that works.
Do this before you leave, not in a hostel lobby on someone else’s Wi-Fi. Move critical logins to an authenticator or a hardware key. Print or write backup codes and put them somewhere that is not the phone. If a service will not leave SMS, decide whether you still need that service on the road. Some banks and old government portals will not negotiate. Those are the ones that keep a number alive.
Home number versus eSIM is a pairing, not a swap you do in a panic. I keep a number I control in the US long enough for the accounts that still couple identity to that SIM. Forwarding or a VoIP I own, with a recovery path that is not “the SMS will find me.” Travel data lives on the eSIM. Mixing those jobs is how you lose both.
Document which services still demand which country. A private note, ugly and accurate. When a SIM swap or a port goes wrong, you want that list more than you want a blog post about privacy. SMS lockout is a self-inflicted outage. The attacker does not have to be clever if you already handed the second factor to a number you cannot receive.
This is not the public Wi-Fi problem. Café networks are a different threat. This is not general account hygiene either, though hygiene helps. This is the coupling between your body, a phone number, and a door you must open from another hemisphere. I learned that the ugly way between New Orleans banks and Auckland mornings.
Hardware keys live on the same ring as the house key I no longer have. Redundant. Easy to hate until the day the SMS never arrives. Set them up at home. Test a login from a second device. Then leave. The kitchen table lockout is optional. I opted into it once. I do not plan to again.
— JV · Dark Heart Labs.