Nearly every travel eSIM sold today is data-only, and the term causes more confusion than any other in the category. It does not mean a limited product. It means the eSIM provides mobile internet and no telephony, and whether that matters to you depends almost entirely on one thing: how your bank sends verification codes.
This guide covers what data-only excludes, which providers make an exception and on what terms, and how to keep receiving the messages you cannot afford to miss.
In this guide:
- What data-only actually excludes
- Who includes a number, and how
- The verification code problem
- Dummy numbers, and why not to use them
- Deciding whether you need a number at all
What data-only actually excludes
A data-only eSIM carries internet traffic and nothing else. There is no telephone number bound to the profile, so the mobile network has no way to route a call or a text to it.
What still works, which is most of what you do:
- Every messaging app: WhatsApp, iMessage, Signal, Telegram, Messenger
- Every calling and video app: FaceTime, WhatsApp calls, Zoom, Google Meet
- Maps, transit apps, ride-hailing, translation, email, browsing, banking apps
- Airline apps, boarding passes, hotel check-in, streaming
What does not:
- A call placed to your mobile number from an ordinary phone
- An SMS sent to your mobile number, including bank one-time passcodes
- Dialling a local number from your phone’s keypad
- Reaching emergency services on that line
That last one deserves a sentence of its own. Most phones will place an emergency call over any available network regardless of which SIM is active, but you should not rely on a data-only travel eSIM as your emergency line. Keep a home line installed, or know the local emergency number and have a way to reach it.
Who includes a number, and how
The picture is more varied than the phrase data-only suggests, and the variation is mostly recent. Every statement below is taken from the provider’s own website or help centre and is correct as at 19 September 2026.
| Provider | Number on travel plans | How it works |
|---|---|---|
| Ubigi | No | States plainly that you will not get a new mobile phone number; mobile data only |
| Airalo | Mostly no | Most eSIMs are data-only with no number; a separate product line advertises data, calls and texts |
| Nomad | No, with one exception | Data-only; the Thailand DTAC plan includes a number with local calls |
| Holafly | No on travel eSIMs | Monthly Plans bought from November 2025 can include a US, UK or Canada number, inbound SMS only, calling app-based |
| Saily | Optional paid add-on | A US number for a small monthly fee, SMS supported, no MMS or call forwarding, identity verification required |
| Viasimo | No | Data-only; keep your home number on your other line |
Three things are worth pulling out of that table.
A number is almost always a subscription, not a one-off. Saily’s number is billed monthly. Holafly’s is attached to a monthly Plan that renews every 30 days. If you buy one for a two-week trip, remember to cancel it, or you will keep paying for a number you are not using.
Inbound only is common. Holafly’s Plans support incoming SMS but not outgoing SMS or traditional outgoing calls; calling is app-based. That is genuinely useful for receiving verification codes and useless for ringing a taxi.
A US number is not a local number. Saily’s add-on is a US number regardless of where you are travelling. It solves the problem of receiving codes at a number you control; it does not give you a local presence in Japan or Italy.
The verification code problem
This is the real reason to care about any of this, and it is worth ten minutes before you fly.
Banks, airlines, government portals and a surprising number of shopping sites still send one-time passcodes by SMS to a registered mobile number. If your home SIM is switched off or removed while you are abroad, those messages go nowhere. Travellers discover this at the worst possible moment, usually while trying to authorise a card payment in a foreign country.
There are three workable approaches.
Keep your home line active alongside the travel eSIM. On a dual-SIM phone this is the standard arrangement: home SIM enabled for calls and texts with its data switched off, travel eSIM handling all data. Receiving a text usually costs nothing even on an expensive home tariff, because you are not using data. Turn your home line’s data roaming firmly off so it cannot quietly bill you.
Move to an authenticator app before you go. Most banks now support an app-based code or a push approval instead of SMS. This is the most robust answer because it works with no mobile signal at all, only internet. It is also the one that takes planning, because changing your security method usually requires you to be at home and verified.
Buy a number as an add-on. Viable, but check the detail. A US number will not receive a code sent to your old number, because you would need to update the registered number with each account, which is exactly the fiddly job you were trying to avoid.
If you take one thing from this guide: check which of your accounts still rely on SMS, and sort those out before departure rather than in an airport queue.
Dummy numbers, and why not to use them
Some data-only eSIMs display a phone number in your phone’s settings. It looks like a normal number. It does not work.
Nomad documents this openly, describing a number shown on some plans that cannot be used for calls, SMS or app verifications. It exists because of how the profile is provisioned on the host network, not because you have been allocated a line.
The practical advice is simple. Do not give it to anyone. Do not enter it as your contact number when booking a hotel or a flight. Above all, do not try to verify an account with it, because the code will be sent into a void and you may lock yourself out of something while abroad.
If you see a number on a plan advertised as data-only, assume it is decorative unless the provider explicitly says otherwise.
Deciding whether you need a number at all
For most leisure travellers the answer is no, and paying for one is money spent on a problem they do not have. Work through these in order:
- Does any account you will need while away send codes by SMS? If yes, and you cannot switch it to an app, you need your home number reachable.
- Will you need to ring local businesses? Restaurants, taxis, tour operators and landlords often do not have an app. A data-only eSIM cannot dial them. Some travellers solve this with a cheap internet calling service rather than a number.
- Is anyone likely to call you on your mobile? Airlines still ring about cancellations, and they ring the number on the booking.
- Does your phone hold two active lines? If it does not, the choice between your home number and travel data becomes a real trade-off rather than a shopping decision.
If you answered no to the first three, a data-only plan is the right product and the cheapest one. Browse destinations to see what a plan costs for your trip, or read our head-to-head provider comparison if you are still choosing between them. If you answered yes to any, the fix is usually your home SIM rather than a purchased number, because it already has the number your accounts know.
Viasimo’s plans are data-only. We say so here rather than in the small print, because the right setup for most travellers is our data alongside your existing number, not instead of it.
