How to use your smartphone abroad: roaming and travel tips

Here's the scary part: without a plan or add-on, roaming charges can sneak up on you in three ways: data (the biggest culprit, since it runs silently in the background), voice calls, and SMS. A single hour of normal phone use could cost more than a full day pass. And yes, many carriers charge you for incoming calls too, which feels particularly unfair when you're just answering a friend's hello from home.

This one is fundamental. Here's how to do it:

iPhone: Settings > Cellular > Cellular Data Options > Data Roaming and switch it off.

Android: Settings > Network > Internet > Mobile Network > Roaming and disable it.

Note that roaming charges can appear on your bill for an additional billing cycle after you return home, because the visited network has to report usage back to your home carrier before it can invoice you. On a dual-SIM phone, it's good practice to check which SIM is set as the active data line and disable roaming on both. On iPhone, you should also turn off "Allow Cellular Data Switching" (Settings > Cellular) to stop the phone from automatically switching between SIM lines.

Good news if you're travelling within the EU: there's a regulation called "Roam Like at Home" (RLAH) that lets you use your home SIM at domestic rates with no roaming charges. You can use it across all 27 EU countries plus Iceland, Liechtenstein, and Norway. Moldova and Ukraine were also included in early 2026.

The catch is a fair-use data cap. If your home plan has unlimited data or incredibly cheap data, your carrier can still cap how much you burn through while roaming. Go over that cap, and you'll face a surcharge. Your carrier must warn you before you hit the limit, but it's worth checking your specific plan's fine print before you travel.

Here's where RLAH doesn't work, and this matters: Switzerland, the UK, Turkey, and Morocco. If you're crossing from an EU country into any of these, expect full roaming charges to kick in. The same goes for mobile connections on ships and aircraft, which sit outside the RLAH zone entirely.

A travel eSIM is a digital SIM profile you download to your phone before departure. It connects to a local network at local rates, so you avoid roaming charges entirely on data. Travel eSIM plans typically cost between €3-5 per GB in most destinations, often cheaper than carrier day passes.

Here's how to check if your phone supports it:

iPhone: Settings > Cellular and look for "Add eSIM".

Android: Settings > Network > Internet > SIMs and look for "Download a SIM".

For multi-country trips, a regional eSIM covering all your destinations is usually cheaper than buying individual country plans. Most regional eSIM plans in Europe run between €3-8 for 1-2 GB over seven days, depending on the provider and coverage area. Install the eSIM before you travel and test it while you still have a reliable connection at home. Keep your home SIM active in the background for calls and texts.

If you're staying in one country for more than a week, a local prepaid SIM card is often the cheapest option per gigabyte. You can find them at airports, phone shops, and convenience stores in most countries. Your phone must be unlocked to use one. Phones bought in Europe and most of Asia are usually unlocked; phones from the US and Canada are more often locked to a carrier. Contact your carrier to request an unlock before you travel, and note that some carriers won't unlock a phone that still has payments outstanding.

When you swap in a local SIM, you get a new local number. Give that number to anyone who needs to reach you. Keep your original SIM somewhere safe. Some countries, including India, require passport registration to activate a local SIM, so carry your passport when you go to buy one.

Wi-Fi calling routes your voice calls and texts over any Wi-Fi connection instead of the cellular network, using your regular phone number. When it works, calls to your home country are treated as domestic calls at your standard plan rate, with no roaming charge. Here's how to set it up:

iPhone: Settings > Phone > Wi-Fi Calling.

Android: Settings > Network & Internet > Mobile Network > Wi-Fi Calling.

Messaging and calling apps like WhatsApp, FaceTime, and iMessage all work over your data connection (whether that's an eSIM, a local SIM, or Wi-Fi) and cost nothing beyond the data they use. The only real limitation is that the person you're calling needs the same app. If you need to call regular phone numbers, there are apps that offer international calling at rates significantly cheaper than your carrier charges, though they're worth comparing before you travel.

One thing to watch out for: standard SMS texts can still be sent and billed even when you've turned off data roaming. Only app-based messaging gets blocked when data is off. So if you're relying on text messages, you might accidentally rack up charges. Stick to Wi-Fi or your eSIM data for texting, and you'll be fine.

GPS on your phone does not use mobile data. The map tiles and routing data do. Download your destination's maps on home Wi-Fi before you leave, and your phone can navigate without any data connection at all. In Google Maps, search for your destination, tap the three-dot menu, and select "Download offline map". Apple Maps has the same feature. Offline maps can be 100 MB or more per area, so download them on Wi-Fi, not on a travel eSIM.

Offline maps in Google Maps do not include step-by-step transit directions, and downloaded areas may expire after a period of time. Refresh them on hotel Wi-Fi if your trip is longer than a couple of weeks.

Your phone generates roaming charges while sitting in your pocket. Background app refresh, cloud photo backups, automatic OS updates, and email push notifications all pull data the moment your phone connects to a foreign network. Turn these off before you board.