Learn about Data-only eSIM

Data eSIMs are a popular choice for travel because they offer flexible internet access, eliminating the need for a physical SIM card. But can this eSIM also make calls? This article will provide the answer, along with instructions on how to use an eSIM for communication while traveling.

What is a data eSIM? Can I make calls with it?

Image source: Pexels

Simply put, a data eSIM is a SIM card that only provides mobile data for you to access the network. It does not come with a phone number and does not support regular calls or text messages.

The main difference between a data-only eSIM and a regular eSIM lies in communication capabilities. A regular eSIM (typically provided entirely by a domestic carrier) comes with its own phone number and supports calls, texts, and internet access. A data-only eSIM, on the other hand, is optimized for internet access, typically for international travel or short-term needs.

However, as long as you have an internet connection, you can still use the app to communicate normally. These are VoIP apps like WhatsApp, Viber, Zalo, Skype, etc., which support both audio and video calls. In fact, many people use a data-only eSIM to stay connected on the go, without a physical SIM card or primary phone number.

How to use an eSIM to make calls while traveling

, Aviro will guide you through some common ways to make calls using only a data eSIM here.

1. Make phone calls through OTT messaging apps

Image source: Pexels

Popular messaging apps like WhatsApp, Zalo, Facebook Messenger, Telegram, Viber, LINE, and more all support voice and video calls over the internet. As long as both you and the instance have the app installed, connecting is easy and completely free, no matter which country you are in.

Advantages:

• Familiar interface, easy to use

• Consume local phone numbers

• Supports video calls and sending files and photos

Note: Some apps, like WhatsApp, require initial phone number verification , so you should switch to a data-only eSIM before launching and logging in.

2. Use a VoIP app to call a phone number

If you need to call a landline or mobile phone, you can use a VoIP (Voice over IP) service, such as:

• Skype : Allows calls to any phone number in the world. You can purchase plans by the minute or top up your account.

• Google Voice (Available in some countries only): Allows you to make and receive calls using your Google number.

• TextNow, Talkatone : Provides you with a virtual phone number to make calls, mainly supported in the United States and Canada.

Advantages:

• Call any phone number, even those who don't use the app.

• Cheaper than using international roaming calls.

Note: Some services require accounts to be set up in a specific country (e.g. Google Voice in the US). You should carefully review the terms of use first.

3. Tips for using eSIM for data to make calls effectively

In addition to understanding app tips, you can also apply the following to help you make more calls and texts using your eSIM:

• Prioritize stable Wi-Fi

• Use 4G/5G network instead of 3G for better sound quality

• Close bandwidth-intensive apps such as YouTube, Netflix, Facebook, TikTok, Spotify, or apps that are downloading data in the background.

• Consider regularly updating your phone software and communication apps for program errors.

• Use a headset with a good quality microphone, clear sound, and noise reduction

• Make sure your phone battery has enough capacity to maintain stable satisfaction

How to activate and use eSIM

Source: Canvas

Before purchasing an eSIM, you need to check whether your device supports eSIM . 

You can purchase a travel eSIM from a service provider like Aviro. After payment, a QR code or activation code will be emailed to you within a quarter.

Next, Aviro will walk you through using your primary phone number and a data-only eSIM while traveling:

1. Keep the primary SIM card always on (do not remove or turn off)

Even if you use an eSIM to access the internet, make sure your physical SIM card (or primary eSIM) (the one containing your phone number) is still turned on. If you remove the SIM card or disable it in settings, you won't be able to make/receive calls or text messages using that number.

2. Turn off "Data Roaming" on the primary SIM card

Go to Settings > Cellular (or Mobile Networks ) on your phone and turn off Data Roaming for your primary SIM card. This will prevent your SIM card from automatically using international data and incurring high charges. 

Also, to ensure you are not using a roaming plan, please proactively call your carrier or your account to make sure you do not have it enabled by default.

3. Enable only eSIM data as the primary mobile data source

To use the Internet abroad and avoid roaming charges , please turn on your travel eSIM immediately and make sure to select the eSIM as the default mobile data source in Settings > Mobile Data.

• For iPhone: Enable data roaming for eSIM.

• For Android: Select eSIM as the primary SIM card for mobile profile.

4. Set the primary SIM card for calls and text messages

To ensure you can still receive/send messages or make calls using your processed phone number:

• On iPhone : Go to Settings > Cellular > Default Line > iMessage & FaceTime and select your primary SIM card.

• On Android : Go to Settings > Cellular > Calls & Messages and select your primary SIM card.

NOTE: You must enable data roaming on your primary SIM card in Vietnam before going abroad.

5. International Calls and Text Messages

Even if you use an eSIM for data transfer, calls or messages made abroad using your primary SIM card will still be charged internationally at your carrier's rates. Best priority interval app plans (such as WhatsApp, Zalo, Viber, Messenger...) Make calls to save money!

A data-only eSIM is a smart choice, allowing you to stay connected while traveling internationally, limiting roaming charges while still making internet calls using popular apps. With the right setup, you'll have a seamless, real-time experience throughout your entire journey. If you don't already have a data-only eSIM, contact Aviro by emailing Sales.VN@avironetwork.com or using the live chat on our website!