In short: eSIM and WiFi calling are two distinct but complementary things: WiFi calling (VoWiFi) uses your Spanish number over any WiFi network, while an eSIM provides mobile data at your destination. You can activate both simultaneously, but only an eSIM guarantees internet upon landing, without relying on your operator allowing WiFi calling outside of Spain.
WiFi calling (or VoWiFi) allows your mobile phone to make and receive calls and messages via a WiFi network when mobile coverage is poor or nonexistent. A common question for travelers is whether this still works when using a data eSIM abroad: the short answer is that WiFi calls depend on your primary line, not the data eSIM, and here's how it all fits together without any nasty surprises on your bill.
What is WiFi calling (VoWiFi)
WiFi calling allows you to make and receive regular calls and SMS using a WiFi connection instead of your operator's antenna. It's your usual number that makes the call; the only difference is that the voice travels over the internet. It's useful when you're in a basement, a hotel with poor coverage, or a rural area with no signal.
The key is that WiFi calling is tied to your primary phone line, the one with your number and your plan. If your operator supports it and you have it activated, your phone automatically switches to WiFi when it detects that there isn't a good mobile network. In Spain, it's offered by Movistar, Vodafone, Orange, Digi, and most MVNOs, although each calls it something different ("Llamadas WiFi," "WiFi Calling," or "VoWiFi").
Be aware of an important nuance for travel: many operators block WiFi calling outside the country of origin. In other words, it works at home, but abroad it might be deactivated due to operator policy. It's advisable to check this before you leave so you don't rely on it.
Does WiFi calling work with a data eSIM?
Yes, but with a nuance: data eSIM and WiFi calling are separate things. The eSIM gives you cheap internet at your destination; WiFi calling uses your Spanish line to make calls. You can have both active at the same time, and each performs its function without interfering with the other.
The best combination for a traveler is simple: you leave your Spanish line installed to receive bank SMS and important calls, activate a data eSIM as your internet line, and deactivate roaming for the Spanish line to avoid extra costs. With that eSIM, you have data, and over that data (or over the hotel WiFi), WhatsApp, Telegram, and video calls work.
Classic WiFi calling would still be tied to your Spanish number, and if your operator allows it abroad, you could receive a normal call without activating roaming, provided you are connected to a WiFi network. Since this is not guaranteed, it's practical to rely on apps over eSIM data. If you want to better understand how this works compared to traditional roaming, we have a complete guide on what data roaming is and another that compares eSIM vs roaming in depth.
How to activate WiFi calling on iPhone
On iPhone, it's quick. Go to Settings > Phone > Wi-Fi Calling and toggle "Wi-Fi Calling on This iPhone" on. The system will ask you to confirm your emergency address (mandatory in the EU). From then on, you'll see "WiFi" next to the operator in the status bar when it's working.
If you're still not sure how your iPhone works with two active lines, take a look at our guide on how to install an eSIM: check which line you activate Wi-Fi Calling on, it should be the line with your number, not the travel data eSIM. You can set the Spanish line as "default for calls" and the eSIM as "default for mobile data."
Tip: if you're traveling, activate Wi-Fi calling on your primary line before leaving Spain. Some operators only allow the first registration within the country, and then it works abroad.
Remember that even if Wi-Fi calling is turned on, it won't consume your data plan because it uses WiFi. And if you're in airplane mode with WiFi active, it might also work depending on the operator.
How to activate WiFi calling on Android (Samsung, Xiaomi...)
On Android, the path varies by brand, but the idea is the same. On Samsung Galaxy: Settings > Connections > Wi-Fi Calling. On Xiaomi: Settings > SIM cards & mobile networks > (your line) > Wi-Fi Calling. On Google Pixel and other pure Android phones, it's usually in Settings > Network & internet > SIM > Wi-Fi Calling.
If you're still not clear on what a virtual eSIM is and how it coexists with your physical line, it's worth reviewing before touching these settings: on Android, once installed, you'll see that you can choose the line for Wi-Fi Calling. Just like on iPhone, activate it on the line with your number, not on the data eSIM. Some Xiaomi and Motorola phones require the option to be enabled by the operator; if it doesn't appear, your company doesn't offer it on that model.
| Mobile | Path to activate Wi-Fi Calling |
|---|---|
| iPhone | Settings > Phone > Wi-Fi Calling |
| Samsung Galaxy | Settings > Connections > Wi-Fi Calling |
| Xiaomi / Redmi | Settings > SIM and networks > Wi-Fi Calling |
| Google Pixel | Settings > Network & internet > SIM > Wi-Fi Calling |
Are WiFi calls free or do I get charged abroad?
This is the tricky part. Wi-Fi calling is not magic: even if the voice travels over Wi-Fi, your operator may charge the call as if you were in your home country or even as an international call, depending on their policy. In many cases, national Wi-Fi calls are charged as if you were in Spain, which is an advantage; but it's advisable to confirm this with your company before traveling.
What is certain is that Wi-Fi calling does not consume your data plan or that of the eSIM, because it uses the Wi-Fi network. The real risk is not confusing it with voice roaming: if your Spanish line has roaming active and you make a call over the mobile network (not Wi-Fi), you will pay for roaming. That's why we recommend deactivating voice roaming for the primary line and relying on the eSIM and apps.
- National Wi-Fi call: usually as if in Spain (verify this).
- Voice roaming call: roaming tariff, can be expensive outside the EU.
- App call over eSIM data: only uses data, no voice cost.
Alternatives for cheap calls with your eSIM
If your goal is to talk without spending, the simplest way is to use your eSIM data with voice apps. WhatsApp, Telegram, FaceTime, Signal, or Google Meet offer quality calls and video calls consuming very few megabytes. With an active data eSIM, you have internet as soon as you land, without having to find WiFi.
For calls to landlines or people without apps, VoIP services like Skype or internet calls offer much lower rates than voice roaming. And if you want to keep your number active to receive verification SMS, leave your Spanish line installed for SMS only and use the eSIM for everything else. You can find more tips for stretching your plan in our guide on how to save data with your eSIM while traveling.
Traveler's tip: a voice call via WhatsApp uses about 0.5 MB per minute. With 1 GB of data, you could talk for hours without coming close to exhausting your plan.
If your next destination is Europe, directly check out the eSIM for Europe plan and install it before leaving home; that way, as soon as you land, you'll have data to call via WhatsApp without looking for WiFi.
What almost no one tells you about WiFi calling and eSIM
Here are the nuances that don't appear in the phone's technical specifications, but that you will encounter in real travel.
Captive WiFi in hotels and airplanes sometimes blocks WiFi calling even if you are "connected." Many WiFi networks with a captive portal (those where you have to open the browser, accept terms, or enter a room number) filter the signaling traffic that VoWiFi needs to register the call. The result: the phone indicates WiFi connected, but the call doesn't go through, and no clear error message appears. If this happens, don't waste time restarting the hotel WiFi: try directly with your eSIM data and an app like WhatsApp, which can usually bypass almost any captive portal without a problem.
A travel data eSIM, like ours, will never be able to activate WiFi calling on its own. And here it's worth being honest: if all you need is to make a few isolated calls using the accommodation's WiFi, you don't need to buy anything; it's enough to activate WiFi calling for free with your Spanish operator on your usual line. The eSIM makes sense when you need data outside a known WiFi network: for real-time maps, to order a taxi, to translate a menu, or to avoid relying on the bar's WiFi working well.
Data roaming and voice roaming are distinct switches on many Android phones, especially mid-range Samsung and Xiaomi models. It's common to disable "data roaming" thinking that everything is blocked, without realizing that calls and SMS over the mobile network (not WiFi) are still routed via separate voice roaming. Before leaving, check both settings separately instead of assuming one includes the other.
On iPhone, airplane mode with WiFi does not always keep WiFi calling active, and on Android, the variation is even greater depending on the manufacturer and the customization layer. If you're flying and need to be reachable in case your operator calls you, check before takeoff that the "WiFi" notification still appears next to the operator's name; if it disappears, you'll have to deactivate airplane mode and only use the loose WiFi switch.
Frequently Asked Questions
What exactly is WiFi calling?
It's normal calls and SMS, with your own number, that travel over a WiFi network instead of through the operator's antenna. They are useful when you don't have mobile coverage but do have a WiFi connection available, such as in hotels, basements, or rural areas.
Can I use WiFi calling and a data eSIM at the same time?
Yes. The eSIM provides internet at your destination and WiFi calling uses your Spanish line to make calls. They are independent and can be active simultaneously. It is common to leave the Spanish line for SMS and the eSIM as the main data line.
Are WiFi calls free?
WiFi calling does not consume your data plan because it uses WiFi, but the call itself may be charged depending on your operator. Many companies charge national calls as if you were in Spain. Confirm this with your operator before traveling to avoid surprises.
Does WiFi calling work abroad?
It depends on the operator. Many block it outside the country of origin due to internal policy. Activate it before leaving Spain and check with your company if it remains active at the destination. If not, rely on voice apps over your eSIM data.
How do I activate WiFi calling on iPhone?
Go to Settings, Phone, Wi-Fi Calling, and toggle the switch. Confirm your emergency address when prompted. You'll see the "WiFi" notification next to the operator when it's working. Do this on your numbered line, not on the data eSIM.
Can I activate WiFi calling over a travel data eSIM?
No. Data eSIMs designed for travel, like those we sell, do not include their own voice number, so there is no line over which to activate WiFi calling. This function always depends on your numbered line, usually the physical one from your Spanish operator.
Why can't I receive a call via WiFi calling if I'm connected to WiFi?
This is common on networks with a captive portal, such as those in hotels or airplanes, where you have to log in from the browser. This type of WiFi can block the traffic that WiFi calling needs to register the call, even if the icon shows a connection. If this happens, try using a voice app over your eSIM data.
Conclusion
WiFi calling and eSIM complement each other: one uses your number over WiFi, the other gives you cheap internet at your destination. To travel with peace of mind, activate WiFi calling before you leave, deactivate roaming on your line, and rely on apps over your eSIM data. With a PuraSim data eSIM, you connect in 1 minute upon landing and talk on WhatsApp without paying roaming fees; explore the plans in our store before your next trip.
