How to keep receiving your bank's SMS codes while abroad on eSIM

Keep your Tunisian SIM in the phone and active for calls and texts, and let a second, travel-only eSIM handle your data — that way your bank’s SMS codes keep arriving on the number they’ve always gone to, while your data doesn’t rack up a roaming bill. This is the whole fix, and it’s simpler than most people expect before they’ve done it once.

Why this specific problem exists

Plenty of banks, especially ones without a dedicated authentication app, still send one-time passcodes exclusively by SMS to the number on file — usually your home number. Switching your phone entirely onto a foreign SIM or turning off your home line to save money means that code stops arriving exactly when you need it most: confirming a card payment, logging into online banking from an unfamiliar Wi-Fi network, or approving a transfer. Losing SMS access is a real, recurring problem for travelers, not a hypothetical one, and it’s one of the most common reasons people search for this exact fix mid-trip rather than before leaving.

It’s also a problem that’s easy to miss when planning a trip, because most people only think about data — maps, messaging apps, browsing — and forget that their bank’s security setup depends on a phone number staying reachable in the traditional sense, by SMS, regardless of what’s happening with data roaming.

The dual-SIM setup that solves it

Most current phones support two active lines simultaneously — one physical or eSIM line for calls and texts, and a second eSIM purely for data. Keep your Tunisian number as the voice-and-SMS line exactly as it already is, install a travel eSIM as a second, data-only profile, and set your phone’s mobile data routing to the travel line while leaving calls and texts on your Tunisian number. Your bank keeps texting the same number it always has, and none of that traffic depends on the travel eSIM at all.

Setting it up before you leave, not after

Setting	What to check
Default line for calls and SMS	Set to your Tunisian number
Default line for mobile data	Set to the travel eSIM
Data roaming on Tunisian line	Turn off, to avoid a roaming bill
Data roaming on travel eSIM	Turn on, this is the line meant to roam

Test this at home before you fly — send yourself a text and confirm data still loads with the travel eSIM active, so you’re not debugging phone settings the first time your bank actually sends a code.

What to do if a code still doesn’t arrive

If a code doesn’t come through despite the setup above, check first whether your Tunisian line still has any signal at all — some destinations have weaker or no coverage from Tunisian carriers’ roaming partners in specific regions, which is a coverage issue rather than a settings one. If the line shows signal but nothing arrives, a short delay of a minute or two is normal for international SMS delivery; requesting a fresh code rather than waiting indefinitely is usually faster. Also worth checking: that data roaming truly is off on the Tunisian line and on for the travel eSIM, since the two settings being swapped by mistake is the single most common reason this setup fails on the first attempt.

A backup worth having regardless

Where your bank offers an authenticator app instead of SMS codes, set it up before you travel — it works over any internet connection, including the travel eSIM’s data, and removes the dependency on your home line’s SMS reception entirely. This isn’t always available, but where it is, it’s a more reliable backup than relying on cross-border SMS delivery from an unfamiliar network.

Why this matters more on a trip than at home

At home, a missed SMS code is a minor annoyance — you retry, it arrives. Abroad, you’re often trying to pay for something time-sensitive: a hotel charge, a ticket booking with a countdown, a transfer before a deadline. Getting the dual-line setup right before you leave means one less thing that can fail at the exact moment you need it to work, and how to manage multiple eSIMs covers the general setup in more depth if this is your first time running two lines together.

Getting the data line right from the start

The Simtegre app is built as a pure data line specifically so it slots into this setup without touching your existing number — buy the plan before you fly, install it as your second profile, and your bank’s SMS line stays exactly where it’s always been. Check current plans for your destination, and the device guides walk through setting the travel eSIM as your data line correctly on the first try.