Is it necessary to turn on data roaming for my device?

Do You Really Need to Turn On Data Roaming?

If you’ve ever landed abroad, turned off airplane mode, and wondered why your mobile data isn’t working, the answer is usually simple — you forgot to turn on data roaming.

That tiny toggle in your phone settings determines whether your device can connect to foreign mobile networks outside your home country. But do you always need to turn it on? Not necessarily. It depends on the type of SIM or eSIM you’re using, and knowing when to enable or disable roaming can save you from both frustration and surprise charges.

Let’s break it down clearly so you’ll always know when to turn on data roaming, how to do it on any phone, and what happens if you forget.

When You Should Turn On Data Roaming

Whether you need roaming on depends entirely on your mobile setup:

🔹 If you’re using your home SIM card

If your SIM is from your domestic carrier (for example, AT&T, Viettel, or Vodafone) and you’re traveling abroad, do not turn on data roaming unless you’ve activated an international data package. Otherwise, your phone may connect to local networks at expensive roaming rates — sometimes costing dozens of dollars per day.

🔹 If you’re using a travel eSIM or international SIM

If your plan comes from a global eSIM provider such as Twise, Gloka, or Airalo, then you must turn on data roaming for your mobile data to work abroad.
 These eSIMs rely on partnerships with local carriers, and roaming enables your phone to automatically connect to those networks.

In short:
 ✅ Turn on data roaming when using a travel or international eSIM.
 🚫 Turn it off when using your home SIM card abroad (unless you want to pay roaming fees).

How to Turn On Data Roaming on iPhone

The steps are simple — it takes less than 30 seconds:

1. Open Settings.

2. Tap Cellular or Mobile Data.

3. Select Cellular Data Options.

4. Toggle Data Roaming to ON.

Make sure Mobile Data is also turned on — otherwise, roaming won’t work even if the setting is active.

💡 Twise Tip: On some iPhones, especially those with dual SIMs or eSIMs, you’ll see separate data options for each line. Be sure to enable roaming for the one you’re using for travel.

How to Turn On Data Roaming on Android

Android devices might have slightly different menus depending on the brand, but the process is similar:

1. Go to Settings.

2. Tap Connections or Network & Internet.

3. Select Mobile Networks.

4. Find Data Roaming and switch it ON.

For Samsung Galaxy users, you can also find this guide directly from the official Samsung Support.

💡 Twise Tip: Some Android phones show “Roaming data” under SIM manager — double-check that it’s enabled for your active travel SIM.

Read more:
Can I recharge or top up my eSIM?
How to check Roaming Data Consumption on iPhone and Android

What Happens If You Don’t Turn It On

Without data roaming, your phone will only connect to Wi-Fi and won’t be able to use mobile data from your travel SIM or eSIM.
 That means:

• No maps when you’re on the road.

• No instant messages or translation apps.

• No travel updates or check-ins on the go.

For travelers relying on eSIMs, this is the #1 reason people think their eSIM “doesn’t work.” In reality, it’s just that data roaming was left off.

Twise Travel Tip

From our experience, the easiest way to stay connected abroad is to turn on data roaming right after installing your eSIM — before you even leave the airport. That tiny switch ensures your travel data plan activates instantly when you land, without needing Wi-Fi or tech support. 

👉 Get your Twise travel eSIM today and enjoy stable, high-speed data in over 190 destinations — no SIM swap, no hassle, just travel.