The vast majority of travel eSIMs are built, right from the network profile, as a "data only" line: your device registers on the local mobile network exclusively for data traffic (browsing, apps, streaming), but it's never associated with a real phone number active on that network. Without an associated number and without registration on the network's voice/SMS domain, there's simply no channel for a call or text to reach you: data goes through, voice doesn't, because technically they're two separate infrastructures running on different paths.

This is why your smartphone can show full data connectivity (4G, 5G, LTE) while at the same time appearing "unreachable" to anyone trying to call that number: it's not an eSIM fault, it's simply a service that, by design, doesn't include that function.

It's the rule, not the exception. Almost all tourist eSIMs on the market — regardless of provider — are designed for a single goal: giving travelers internet access in dozens or hundreds of countries, at the lowest possible cost and with the simplest possible activation. Including voice and SMS would require additional roaming agreements with every single local carrier, a more complex infrastructure, and consequently a more expensive, less scalable product on a global level.

The real issue, almost always, isn't the eSIM itself: it's the expectation with which it's bought. Anyone used for years to a physical home SIM, which by default bundles calls, texts and data into one package, assumes any SIM — physical or electronic — works the same way. Travel eSIMs, in most cases, don't, and it's essential to know that before departure, not discover it when an OTP fails to arrive.

A "data-only" eSIM gives you exclusively a local roaming internet connection: no phone number is assigned, no voice registration, no ability to natively receive texts. It's the most common and generally most affordable type of eSIM, perfect for anyone who "just" needs to browse, work, use maps and communicate through internet-based apps.

An eSIM with a real mobile phone number is instead a complete line: on top of data for browsing, it assigns you a genuine mobile number, able to receive texts (including OTP codes) and, depending on the plan, incoming calls too. It's the product category built exactly for those who don't want to give up classic phone reachability while traveling.

Your home SIM works differently because it's the product of a direct contract with a carrier that assigned you a number, a full voice, SMS and data profile, and that manages international roaming through bilateral agreements with foreign operators when you travel. A "one-trip" travel eSIM, designed for a single stay, doesn't come from that same type of contract: it's a leaner commercial product, optimized for data, distributed globally precisely because it's simpler to manage at scale.

In other words: you're paying for what the product promises to deliver — affordable mobile data in roaming — not for a service fully equivalent to your main phone line, unless you specifically choose an eSIM that includes a number.

If the eSIM you installed is a "data-only" profile — as most on the market are — the answer is yes, though not in the sense of a malfunction: it's simply a service that doesn't handle incoming SMS, so no OTP code addressed to that profile can reach you, for the same reason a call can't. Your bank's OTP code, if tied to your home number, will keep arriving normally on that line, as long as you haven't deactivated it or removed the physical SIM from your phone.

The problem shows up when, on top of installing the eSIM for data, you also deactivate your main line thinking you're "simplifying" things: at that point neither line can receive the SMS, and the banking transaction stays blocked.

Yes, and it's by far the simplest and most widely used solution among travelers: most modern smartphones support dual SIM mode, letting you keep your home physical SIM (or eSIM) inserted and active for voice and SMS, while a second travel eSIM handles data exclusively. Just turn off data roaming on the home line to avoid unwanted charges, and set the eSIM as the default data line in your phone settings.

This way your number stays fully reachable for calls and texts exactly as if you were at home, while all your browsing runs on a dedicated data connection, typically far cheaper than traditional roaming on your main line.

Yes, and this is worth clarifying: once your account is already registered and verified on a number, WhatsApp runs entirely over an internet connection. It doesn't need that number to be "active" on a telephone network in the classic sense — any data connection is enough, even one from a "data only" eSIM with no voice or SMS. The same applies to most internet-based messaging apps (Telegram, iMessage over WiFi, video calls in work apps).

The issue only arises in specific cases: if you need to reinstall the app, switch devices, or if WhatsApp requires a new security verification, because at that point you need to receive an SMS or call on the registered number, which a data-only eSIM can't provide.

Emergency calls (112 in Europe, and local equivalents elsewhere) are a special case compared to normal voice traffic: by law, in many countries a device can reach emergency services using any available mobile network in the area, even without an active voice-profile SIM or, in some cases, without any SIM inserted, as long as there's network coverage. This behavior depends on the operating system and local regulations, so it shouldn't be considered 100% guaranteed in every country and situation.

For this reason, if you expect to need quick access to local numbers — not just emergency services, but also hotels, taxis, support lines — the most solid solution remains having a line with a real voice profile available, either your home SIM kept active or an eSIM with a real phone number.

In practice there are two solid approaches, and they're not mutually exclusive. The first, simpler and used by most travelers: keep your home SIM (physical or eSIM) inserted and active for voice and SMS only, turning off data roaming to avoid costs, while a dedicated travel eSIM handles all your internet browsing. The second, for those who travel frequently or prefer a number entirely dedicated to travel: choose from the start an eSIM that includes, alongside data, a real mobile phone number able to receive texts and calls.

There's no single "best" solution in the abstract: it depends on how much you travel, how comfortable you are managing two profiles on the same phone, and how critical it is for you to receive OTPs and calls on a specific number.

It's an eSIM that, unlike data-only profiles, assigns you a complete line: a real mobile number, able to receive texts (including bank OTPs) and, depending on the plan, incoming calls too, alongside the data connection for browsing. It's no longer just internet access: it's effectively a second, fully operational phone number, which you can also use to register WhatsApp or other services requiring SMS verification, without touching your home SIM.

No, almost never. Installing an eSIM adds a new network profile to your phone, without touching the physical SIM already present: the two lines coexist and can be managed separately from the device's cellular settings, letting you decide which one handles data, which one handles voice/SMS, and how to set the priorities. Most recent smartphones support this dual SIM configuration without any particular limitation.

The only practical thing to watch is correctly setting which line should handle data (usually the cheaper travel eSIM) and which should remain your reference line for calls and texts, to avoid the phone accidentally roaming on your home SIM and generating unexpected charges.

Yes, and this is an operational detail worth knowing clearly before scanning the QR code: on most fixed-day plans, activation — and therefore the countdown of validity days — starts right when the eSIM profile is installed on the device, not from when it's first used abroad. Installing the eSIM too far ahead of departure can mean "burning" validity days while you're still at home.

A second technical point, equally important: the eSIM profile is downloaded from a server at the moment of installation, so an active internet connection is required at that exact moment. If you install the eSIM the day before departure or on the day itself, make sure you have a reliable WiFi connection available — at home, at the office, at the airport — because without internet the profile download simply can't complete.

If your only need is browsing — email, maps, social media, remote work — a standard BLIVALE data eSIM, dedicated to your destination or to the global coverage you need, is the simplest and most affordable choice: you'll keep receiving calls and texts on your home SIM left active, following the dual SIM setup described in this guide.

If instead you travel very frequently, need to reliably receive bank OTPs or verification texts, or prefer a number entirely dedicated to travel without depending on your home SIM, the right choice is a BLIVALE eSIM with a real mobile phone number, available both for Europe and globally, which combines data and phone reachability in a single profile.

If you also work from a laptop or tablet while traveling, sharing the eSIM's data connection via hotspot with other devices is often essential — for a work video call from your computer, or handling documents on the move. The ability to turn on hotspot is independent of whether the eSIM includes a phone number: it's purely about the data component.

The BLIVALE Unlimited Premium and eSIM BLIVALE Unlimited Smart plans include hotspot, making them suitable for all travelers with multiple devices and for families. Most of the remaining BLIVALE eSIMs also offer hotspot as an available option: however, if you plan to use it intensively — several devices connected at once, for many hours a day — the Unlimited Premium eSIMs remain the best choice.