Hands-on

How to call on a data-only eSIM: apps, texts and your number

How to call and get texts when your travel eSIM is data-only: calls in messaging apps, bank codes on your home SIM, how much data a call uses and when you need a regular number.

Published September 9, 2026 · Updated October 1, 2026 · 8 min read · MoreSim editorial team

If your travel eSIM is data-only, you make calls through messaging apps: a voice call in Telegram, WhatsApp or FaceTime runs over mobile data and uses your plan’s gigabytes, not money from your home account. Texts from your bank still reach your home SIM, which stays in the phone as a second line. MoreSim plans are data-only, with no phone number, so for calls to regular numbers you use your home SIM while roaming or an app that calls landlines and mobiles over the internet.

How to call on a data-only eSIM: messaging apps instead of minutes

A voice call in Telegram, WhatsApp or FaceTime goes over the internet, so it doesn’t matter which SIM provides the data. If the eSIM is set as your mobile data line, the call uses your plan’s gigabytes, not money from your home account. The person you’re calling doesn’t need to set anything up — they just need the same app.

People tend to remember logins too late: many messaging apps confirm your login with an SMS code. Update your apps and check that you’re logged in while you’re still at home. If you have to log in again on the trip, the code will go to your home number, and whether you receive texts while roaming depends on your carrier’s terms.

While you’re at it, agree with family on which app you’ll use and ask them not to call your regular number unless it’s urgent. If your hotel or guide messages you in an app, save their contacts there too. That way every conversation runs over the eSIM’s data.

How much data does an app call use?

A voice call in a messaging app uses little data, while a video call uses many times more. The exact amount depends on the app, network quality and whether the camera is on, and a long video call quickly eats through a small plan. The easiest thing is to measure your own usage in advance.

1. At home, turn off Wi-Fi and note how much data the messaging app has already used, from the stats in your phone’s settings.
2. Make a five-minute test voice call and see how much the number went up.
3. Do the same with video and compare the results.
4. Estimate how many calls you’ll make on the trip and get a plan with some headroom.

Don’t forget the background, either. Messaging apps automatically download photos and videos from chats, and in a busy group chat that can eat more data than all your calls for the day. Turn off media auto-download on mobile data and let it wait for Wi-Fi.

Texts, bank codes and your home number

A MoreSim eSIM installs as a second line, so your home SIM stays in the phone along with your number. If you keep that line turned on, it can receive texts, including verification codes from your bank. Your home carrier charges for incoming calls and texts while roaming, so check its terms before you leave.

Turn off mobile data on your home SIM so you don’t end up online through your home carrier. Keep the line itself on if you’re expecting texts from your bank — that only works if roaming is available on your home plan. On iPhone, also check that automatic switching of cellular data between lines (Allow Cellular Data Switching) is off; menu names depend on your iOS version. Otherwise, when the signal is weak, your phone may switch to data over your home SIM.

If your bank lets you approve transactions with notifications in its app, that’s more convenient than texts when you travel: these notifications arrive over the eSIM’s data. Check this setting before you leave, not while you’re paying at a store.

Where are calls in messaging apps restricted?

An app call only goes through if the app isn’t restricted where you are or where the other person is. As of October 2026, that matters most for calls to Russia and for trips to the UAE. The list includes only restrictions confirmed by regulators or by major news outlets citing them.

• Russia. Since August 2025, the regulator Roskomnadzor has partially restricted voice calls in Telegram and WhatsApp. In February 2026 it confirmed slowing down Telegram, and WhatsApp’s domains were removed from Russia’s national domain name system, according to RBC and Kommersant. A call to someone in Russia through these apps may fail even when your own data works fine.
• UAE. Under the TDRA’s rules, internet calling is only allowed through services it has licensed or approved, and carriers must block the rest. WhatsApp calls on local networks don’t go through, according to Gulf News and Khaleej Times reporting in 2026, while messaging works.
• Other countries. Some other countries also have stricter rules for internet calls, and these change over time. Check the news for your destination before you go.

You don’t need workarounds here: agree with family in advance on an app that works for both of you, and keep a regular call from your home SIM while roaming as a backup for important conversations. Save the local emergency number in your phone as well — it works whatever plan you’re on.

When do you need a real phone number?

You need a real number when the person you’re calling doesn’t answer in messaging apps: a hotel, a transfer driver, your bank’s or airline’s support line. MoreSim plans are data-only, with no phone number, so for those calls you have other options.

• A regular call from your home SIM while roaming, at your carrier’s rates — for rare, short calls.
• Wi-Fi calling from your home carrier, if both your carrier and your phone support it. Check in advance whether it works abroad.
• Apps that make internet calls to regular phone numbers. Their terms vary, so compare them before your trip.
• A local SIM with a number, if you’ll often call local numbers. You buy it on arrival, and some countries require a passport.

Note down the emergency number for your destination in advance — you’ll want it whatever plan you have. Keep it in your notes along with your hotel’s address.

How to set up your phone before you fly

To call over your eSIM’s data without missing bank texts, update your messaging apps, install the eSIM and decide what to do with your home SIM before you fly. It takes about ten minutes, and it’s best done at home while you have Wi-Fi and your home network.

1. Update your messaging apps and make sure you’re logged in.
2. Install your MoreSim eSIM over Wi-Fi while you’re at home.
3. When you land, set the eSIM as your data line and turn on data roaming for it: most travel eSIMs connect to a local carrier as a roaming network, and without it you won’t get online.
4. Turn off mobile data on your home SIM, but keep the line itself on if you’re expecting texts from your bank.
5. Save the contacts of family, your hotel and whoever is meeting you in your messaging app.