Keeping Your US Mail, Phone Number and Two-Factor Codes Working

The most stressful admin problem after a move is often not a visa or a tax form. It is a US bank that sends a one-time code to a phone number you no longer have, or a letter from a government office that sits unopened at an old address. Both are easy to prevent before you leave, and harder to fix afterwards.

This guide covers three things: your mail, your US number, and your two-factor authentication.

1. Your mail

Letters do not stop when you move. Banks, the IRS, your state, insurers and old employers will keep writing to the last address they have.

Options:

• A trusted person's address. A relative or friend who agrees to open and scan important mail. Simple and cheap; it depends on their time and goodwill.
• A virtual mailbox or mail scanning service. A US street address where mail is received, scanned and, if you ask, forwarded. Read the terms carefully, including identity checks and what happens to mail you do not collect.
• A package forwarding service. Focused on parcels rather than letters. See Package forwarding explained.

Whatever you choose:

• Update your address with your bank, card issuers, brokerages and insurers.
• Check which address your state and the IRS have for you. See US taxes from abroad.
• Switch to electronic statements where you can.
• Keep a list of who has which address.

2. Your US phone number

Many US services, especially banks, send codes by SMS and do not accept foreign numbers. If your US number is canceled, it can be reassigned, and getting back into accounts can be hard.

Ways to keep a US number alive:

• Keep your carrier plan, often on a lower-cost plan, and use it with roaming or an eSIM. Check whether your plan allows long-term use abroad.
• Port the number to a service designed to keep a number alive cheaply. Check that the services you rely on accept the new type of number before you port; some banks reject numbers they classify as internet-based.
• Keep a basic line on a second SIM or eSIM. Many phones support two lines.

Test it before you leave. Send yourself a code from each bank and confirm it arrives while you are using your local SIM. See Staying connected abroad.

3. Your two-factor authentication

SMS is the weakest and most fragile form of two-factor authentication. Where a service allows it, move to something that does not depend on a phone number:

• An authenticator app on your phone.
• A passkey stored in your phone or password manager.
• A hardware security key, kept in a safe place.

Do this before you leave:

1. List your important accounts: email, banks, brokerages, tax, health, government and your password manager.
2. For each one, add an authenticator app or passkey, if offered.
3. Download and print the backup codes. Store them somewhere safe, not only on your phone.
4. Add a second method where possible, such as a second key or a trusted device.
5. Make sure your main email account is the most protected of all; it is how every other account is reset.

When you travel

• Logins from a new country can trigger a security block. Tell your bank you are abroad if they offer a travel notice.
• Some US sites block foreign connections. Some people use a VPN to reach them; check the service's terms first.
• Keep your phone safe. It now holds your codes. See Phone theft.

Checklist

1. Choose how your US mail will be received and scanned.
2. Update your address with every financial institution.
3. Decide how to keep your US number, and test codes while abroad.
4. Move important accounts from SMS to an app, passkey or key.
5. Print and store backup codes.
6. Protect your main email account most of all.

Common questions

Can I just use my new local number? Some services accept it. Many US banks do not. Check each one.

What if I am already locked out? Contact the service through its official site and ask for its account recovery process. Have your identity documents ready.