A data-only eSIM doesn't mean a silent trip. You can still call home, message your hotel, and ring a tour operator, just in a slightly different way. Instead of using the phone network, calls go over the internet, which is usually free and often clearer than a roaming call.
Here are four ways to make calls with a data-only eSIM, how much data each one uses, and what to do in the few situations where only a regular phone call will work.
In this guide:
- What a data-only eSIM can and can't do
- 1. Internet calling apps
- 2. Local messaging apps
- 3. Wi-Fi Calling on your home number
- 4. Your home line, with roaming
- When you really need a phone call
- How much data do calls use?
- FAQs
What a Data-Only eSIM Can and Can't Do
A data-only eSIM gives your phone mobile internet at your destination, but no phone number. All egoViet eSIMs work this way. That keeps them cheap, and in practice it covers almost everything: maps, ride-hailing, bookings, social media, and calls through apps.
What it can't do on its own is make a standard call through the phone network or receive SMS. For that, you either use your home line (more on that below) or an app that calls over the internet. If you want the full picture, read our guide to eSIMs and phone numbers.
1. Use an Internet Calling App
This is the easiest and cheapest option. These apps make voice and video calls over your eSIM data, with no roaming charges:
| App | Best for | Good to know |
|---|---|---|
| Almost everyone, worldwide | Keeps working with your usual number, even when that line isn't giving you data | |
| FaceTime | Calling other iPhone, iPad, and Mac users | Works with your Apple Account email, so a data-only line is no problem |
| Messenger and Instagram | Friends who live on social media | Voice and video calls straight from your chats |
| Telegram and Signal | Private, encrypted calls | Your contacts need the same app |
Before you rely on app calls, make sure your phone is eSIM-compatible and your travel eSIM is installed. The only catch is that the person you call needs the same app. Before you leave, agree with family and friends on which app you will use, so nobody is left calling a number that doesn't answer.
FaceTime not connecting? Go to Settings > Apps > FaceTime (or Settings > FaceTime on older iOS) and make sure your Apple Account email is ticked under "You can be reached by FaceTime at".
2. Use the Messaging App Locals Use
In many countries, businesses answer messages faster than calls, and they do it on one specific app. Install the local favorite before you go:
- Japan, Thailand, and Taiwan: LINE
- South Korea: KakaoTalk
- Vietnam: Zalo
- China: WeChat
- Most of Europe, Latin America, and the Middle East: WhatsApp
Hotels, guesthouses, tour companies, and even drivers often list these accounts on their booking pages. A quick message also beats a phone call when there is a language barrier, because you can paste in a translation.
3. Use Wi-Fi Calling on Your Home Number
Many carriers offer Wi-Fi Calling, which lets you make and receive regular calls and texts on your home number over a Wi-Fi connection. Some carriers charge calls home at domestic rates when you use it abroad, but rules vary a lot between providers and countries.
Turn it on before you travel in Settings > Cellular > Wi-Fi Calling on iPhone, or in your phone app's call settings on Android. Then check your carrier's website for how it bills Wi-Fi calls made abroad.
4. Use Your Home Line, With Roaming
Your physical SIM can stay switched on next to your eSIM, so you can still make a normal call on your usual number. Your phone keeps using the eSIM for data and only uses your home line for the call itself. Our guide to using an eSIM and a physical SIM at the same time shows how to set this up.
Keep in mind that your carrier will charge roaming rates for these calls, and often for incoming calls too. Keep this option for short, important calls, and make sure data roaming is off on your home line. Read how to avoid roaming charges while traveling to keep the bill under control.
When You Really Need a Phone Call
A few situations still call for a regular phone line. Here is how to handle each one with a data-only eSIM:
- Emergencies: Learn the local emergency number before you arrive (112 works across the EU and in many other countries). Phones can usually place emergency calls on any available network, but don't rely on that alone. Save your hotel's address and your embassy's number offline too.
- Banks and verification codes: Keep your home line on so SMS codes reach you. Many banking apps also let you approve logins inside the app instead.
- Airlines: Most airlines have live chat in their app or on WhatsApp, which is often quicker than holding on the phone.
- Restaurants and small businesses: Try their WhatsApp, LINE, or social media account first. If they only take calls, ask your hotel's front desk to call for you.
How Much Data Do Calls Use?
App calls are lighter than most people expect. As a rough guide:
| Call type | Approximate data use | 30 minutes a day for a week |
|---|---|---|
| Voice call | 0.5–1 MB per minute | around 100–200 MB |
| Video call | 5–10 MB per minute (more in HD) | around 1–2 GB |
If you plan regular video calls home, choose a plan with some extra data. If you mostly send voice notes and texts, even a small plan is plenty. Browse plans for your destination in the egoViet eSIM store.
FAQs: Calling With a Data-Only eSIM
Can you make phone calls with a data-only eSIM?
Yes, through internet calling apps like WhatsApp, FaceTime, or Messenger. You can't make a standard network call on the eSIM itself, but you can keep your home line switched on for that.
Does WhatsApp work with a data-only eSIM?
Yes. WhatsApp is linked to the number you registered with, not to the SIM that provides your data. Your account, chats, and contacts stay the same.
Does FaceTime work with a data-only eSIM?
Yes. FaceTime can use your Apple Account email instead of a phone number. If it doesn't connect, check that your email is selected in the FaceTime settings.
Can I receive SMS with a data-only eSIM?
Not on the eSIM itself. Keep your home line switched on to receive texts on your usual number, and check whether your carrier charges for texts received abroad.