To turn on data roaming, open Settings > Cellular > Cellular Data Options and switch on Data Roaming. If your iPhone has two lines, tap the line you want to use first, then tap Cellular Data Options. In the UK and some other regions, the menus are called Mobile Service and Mobile Data Options.
The switch only gives your iPhone permission to use data on another carrier’s network. What it costs is up to your carrier and plan, so check your travel rates before you land.
What data roaming actually does
Apple describes Data Roaming as the setting that allows internet access over a cellular network in places your own carrier doesn’t cover. That usually means another country. With it off, your iPhone may still show a partner network’s signal and let you make calls, but web pages, maps and apps won’t load over cellular.
Anything you do on Wi-Fi is unaffected. The roaming switch only controls cellular data.
Check your plan before you turn it on
Some carriers include international data on certain plans at no extra cost. Others charge a daily travel pass or bill by the megabyte. Before your trip, find out:
- If your destination is covered by your plan.
- If you need to add a travel pass in advance, or if it starts automatically the first time you use data abroad.
- How much high-speed data you get and what happens when you run out.
If your carrier’s rates are high, a travel eSIM from a local or international provider is often cheaper. Apple lists eSIM travel plans for more than 190 countries and regions in its cellular data roaming guide.
How to turn on data roaming (one line)
- Open Settings.
- Tap Cellular (or Mobile Service).
- Make sure Cellular Data is switched on. Roaming does nothing if cellular data itself is off.
- Tap Cellular Data Options. The row shows Roaming Off or Roaming On next to it on many carriers.
- Turn on Data Roaming. The switch turns green.
To confirm it’s working, turn off Wi-Fi and open a web page. If the page loads, you’re roaming. Turn the switch off again when you get home, or any time you want to be sure you won’t use cellular data abroad.
How to turn on roaming with Dual SIM or a travel eSIM
Data Roaming is set separately for each line, so you choose which number is allowed to roam.
- Open Settings > Cellular.
- Under SIMs, tap the line you want to use for data abroad.
- Tap Cellular Data Options.
- Turn on Data Roaming for that line.
- Go back to the main Cellular screen, tap Cellular Data, and select the same line.
If you bought a travel eSIM, turn on roaming for the travel line and leave it off on your home line. According to Apple’s eSIM travel guide, keeping your home line active lets you still get calls, texts, iMessage and FaceTime on your usual number, but you might still pay roaming fees on that line. On the Cellular Data screen, also check that Allow Cellular Data Switching is off if you don’t want your iPhone to fall back to the home line for data.
Need to add the travel line first? See our guide to setting up an eSIM on your iPhone. With iOS 26 or later, Apple says your iPhone can turn the travel eSIM off and your home SIM back on automatically when you return.
What about Voice Roaming?
Some carriers also show a Voice Roaming switch in Cellular Data Options. Apple notes it applies to CDMA networks, where turning it off avoids charges for calls made on other networks. If you don’t see it, your carrier doesn’t use it, and calls abroad are controlled by your plan instead.
How to keep roaming charges down
Background activity can burn through a small travel allowance fast. A few changes help:
- Turn on Low Data Mode. In Cellular Data Options, tap Data Mode and choose Low Data Mode (on some models it’s a switch instead). It pauses automatic updates and background tasks like Photos syncing. Our article on Low Data Mode explains where the setting lives and how to switch it back.
- Block data-hungry apps. Scroll down on the Cellular screen and turn off cellular access for apps you don’t need abroad, such as video streaming apps.
- Download before you go. Save offline maps, playlists and shows over Wi-Fi at home.
- Be careful with hotspot. Devices connected to your iPhone’s Personal Hotspot use your roaming data too, and laptops can use a lot.
Your data total for the current period appears at the top of the Cellular screen, so check it every day or two while you travel.
Data roaming is on but there’s no internet
Work through these checks in order:
- Confirm Cellular Data is on and, with Dual SIM, that the line you set to roam is the one selected under Cellular Data.
- Go to Settings > General > Date & Time and turn on Set Automatically. Apple lists a wrong date or time as a cause of connection problems abroad. You can also set the time zone yourself if the automatic option isn’t picking up your location.
- Turn on Airplane Mode, wait about 10 seconds, and turn it off. This makes your iPhone search for networks again.
- Check for a carrier settings update in Settings > General > About. If one is available, a prompt appears after a few seconds.
- Restart your iPhone.
If you have signal but still no data, the problem is usually on the account side. Contact your carrier to confirm international roaming is turned on for your line and that your travel plan covers the country you’re in.
Common questions
Should I leave Data Roaming on all the time?
It’s safest to keep it off unless you’re traveling with a plan that includes roaming. While you’re inside your carrier’s own network, the switch usually has no effect, so leaving it off at home costs you nothing.
Does turning off Data Roaming stop calls and texts abroad?
No. It only blocks cellular data. Calls and SMS texts can still come through and may be billed at roaming rates, depending on your plan. To stop everything on a line, turn on Airplane Mode and reconnect to Wi-Fi, or turn that line off in the Cellular settings.
Why don’t I see Data Roaming in my settings?
Look inside Cellular Data Options rather than on the main Cellular screen. With two lines, you have to tap a line before the option appears. If a line is turned off or has no active plan, its roaming settings may be unavailable.
Matthew Roberts is the founder and editor of ARS Digitech. He started the site to answer the iPhone questions his friends and family kept asking him, and it has grown into a library of iPhone and iOS how-to guides. Matthew writes and maintains every tutorial on the site, checking steps and menu names against Apple’s official support documentation and updating guides when an iOS release moves a setting.