How to keep getting your bank's SMS codes while you travel

Why the code follows your number

Since European payment rules introduced strong customer authentication, banks have to check who you are with at least two independent factors: something you know (a PIN or password), something you have (a card or a mobile phone) and something you are (a fingerprint or your face). The Banco de España explains that the usual way of proving the second one is a one-time password sent by SMS, valid for a short time and impossible to reuse.

That SMS is addressed to a phone number, the one on file at your bank. A data-only eSIM has no number, so it cannot receive it. What it can do is carry the internet traffic while your own line, still installed in the same phone, takes care of the texts. The settings for that split are in our dual SIM guide.

Inside the EU, receiving the text costs nothing extra

Under the EU roaming rules, you are not charged extra to receive calls or texts while roaming in another EU country. The same regime covers Iceland, Liechtenstein and Norway. So a bank code landing on your Spanish, French or German number in Italy does not add anything to your bill.

Two exceptions are worth knowing. On a plane or a ship your phone may connect to a satellite network, and the EU rules do not apply there. Outside the EU and EEA, roaming is whatever your contract says, and the European Commission itself warns it can be expensive. Before a trip to Morocco, Turkey or the United States, ask your operator what an incoming SMS costs in that country. If the answer is unclear, the in-app approval below avoids the question.

Data off on your line, the line itself on

• Keep your usual SIM or eSIM installed and switched on for the whole trip.
• Turn off mobile data and data roaming on that line only, so it never touches the internet.
• Choose the travel eSIM as the line for mobile data.
• Check on arrival that your usual line shows a network name or signal bars, not No Service.

Turning off the whole line is the mistake that locks people out of their bank: no line, no SMS. On iPhone, Apple notes that when data roaming is on for the data line, MMS and Visual Voicemail stop working on the voice-only line, but ordinary text messages, which is how codes arrive, are not on that list.

Set up in-app approval before you fly

Most banks let you confirm payments and logins inside their own app, with a notification you approve with your PIN, fingerprint or face. The Banco de España recommends this kind of alternative to SMS where possible and notes that most banks offer it. The advantage when travelling is that the approval travels over the internet, so the data eSIM carries it just as well as hotel Wi-Fi.

Do the activation at home, a few days before leaving. It can involve confirming your identity or a code, and that is easier with your own network and time to call the bank if something fails. Then test it: make a small online purchase or log in from a laptop and check that the approval reaches the phone.

When the code does not arrive

First look at the status bar. If your usual line shows No Service, the code cannot reach you: restart the phone, then try picking a network manually in that line's settings. Also check that the phone is not filing messages from unknown senders away from your main inbox.

If your line drops to No Service suddenly and stays there while other phones around you work, take it seriously. The Banco de España describes SIM duplication fraud, where a criminal gets a copy of your SIM to receive your codes, and advises contacting your operator straight away and checking your accounts for strange movements. Abroad you can do both over the internet on the travel eSIM.