Data Roaming Not Working: How to Fix Your Phone Abroad

The plane lands, airplane mode goes off, and your status bar says No Service. Or you have bars and nothing loads. You can't open a map or call a ride. When data roaming is not working, three things cause most of it: the roaming switch on your phone, your carrier plan, and the local network your phone picked. Work through the steps below in order. They come from Apple, Google, Verizon, AT&T, and T-Mobile.

In short:

  • No Service or Searching: airplane mode for at least 15 seconds, restart, then pick a network by hand.
  • Bars but no data: turn on data roaming for the right line, then check that your plan works in this country.
  • Very slow data: you probably hit a high-speed limit.
  • Still stuck: find Wi-Fi, then call your carrier or set up a travel eSIM. Only an unlocked phone can take one.

Start with what your screen shows

What you seeWhat it meansGo to
No Service or SearchingThe phone isn't connected to any cellular networkSteps 3, 4, 5
Bars, but no dataA network was found, and the problem is settings or your planSteps 1, 2, 6
Data works but crawlsYou likely reached a limitStep 8

Apple says SOS appears only in Australia, Canada, and the US. So on most trips you will see No Service, not SOS. If you do see SOS in Canada, follow the same steps.

These steps are for your US line. If you use a travel eSIM, they mostly apply to that line too, but pick the eSIM line in each menu.

1. Turn on data roaming for the right line

Your phone won't use a foreign network for data until this switch is on. AT&T says cellular data abroad needs data roaming on and airplane mode off. Verizon says the same about roaming.

  • iPhone: Settings > Cellular, turn on Cellular Data, tap Cellular Data Options, turn on Data Roaming. With two lines, tap the line first. Apple's iOS 27 guide calls this item Options.
  • Samsung: Settings > Connections > Mobile networks, then turn on the roaming switch. AT&T calls it International Data Roaming.
  • Pixel: Settings > Network & internet > SIMs, pick your SIM, then turn on Roaming.

With two lines, also check which line carries data. On iPhone, go to Settings > Cellular > Cellular Data and select the line.

T-Mobile only: its checklist says to dial #RON# or #766# to enable data roaming. Destinations outside its Simple Global list need this step. To turn it off later, use #ROF# or #763#.

2. Check that your plan works here

The switch only opens the door. Your plan still has to allow it. Each carrier has its own traps, as of October 30, 2026:

CarrierWhat to check
VerizonTravelPass comes with Unlimited Plus and Unlimited Welcome. To add it, text TRAVEL to 4004 or use My Verizon. Without a plan you pay as you go. International data is blocked once unbilled use hits $500.
AT&TInternational Day Pass works in over 210 destinations at $12 per 24 hours on land and $20 at sea. Added lines on the same account cost $6 on land.
T-MobileLook for a blocking service on your line. T-Mobile lists an international roaming block as a possible cause. It also says data roaming is off for some destinations, such as cruise ships.

Verizon adds one more warning. Some newer SIM cards and eSIMs can have limited service in certain countries while local operators update their networks. Check its international coverage map for your country. If you have Wi-Fi, also use Verizon's Device Troubleshooting Assistant and search for "Turn data roaming on or off."

To see what a day of roaming really costs, read our TravelPass comparison.

3. Airplane mode, then restart

This sounds too simple, but it is Apple's first step. Turn on airplane mode for at least 15 seconds, then turn it off. If that does nothing, restart the phone. T-Mobile also lists a restart and checking that airplane mode is off.

Give the phone a few minutes after that. It has to find a network that accepts your carrier.

4. Pick a network by hand

Your phone normally picks a partner network by itself. When it doesn't, turn off automatic selection, wait for the list, and try the networks one by one.

  • iPhone: Settings > Cellular > Network Selection, then turn off Automatic. With two lines, tap the line first.
  • Samsung: Settings > Connections > Mobile networks > Network operators.
  • Pixel: Settings > Network & internet > SIMs, pick your SIM, then Network.

T-Mobile suggests trying every roaming partner's network at least three times. Near a border, Verizon notes that your phone may join another country's network if that signal is stronger. Verizon will text you the rates when that happens.

Switch back to automatic when you get home.

5. Check your line and mobile data mode

  • Line is off. On a Dual SIM iPhone, go to Settings > Cellular and select each line. If one is off, tap Turn On This Line. If you turned your US line off before the flight, this is the fix.
  • Wrong network mode. On iPhone, go to Settings > Cellular > Cellular Data Options > Voice & Data, and pick LTE. On Samsung, look for Network mode under Mobile networks. On Pixel, look for Network type in your SIM's settings. If your data drops while you see a 5G icon, LTE is worth a try.
  • Older iPhone. On iPhone 6 or later with No Service, Apple says to update iOS, then turn on Enable LTE in Cellular Data Options.

6. Check your APN and VPN

If roaming is on and your plan is fine, look at the phone's data settings. T-Mobile lists two things: the APN protocol should be set to IPv4/IPv6 Auto or IPv4 Only, and you should turn off any VPN settings or apps.

On Samsung, Access Point Names sits under Mobile networks. If you changed something and got lost, the menu there lets you reset to default. Don't edit an APN by guessing. Ask your carrier for the right values.

7. Update carrier settings and iOS

You need Wi-Fi for this. On iPhone, connect to Wi-Fi and go to Settings > General > About. If a carrier settings update is ready, the phone offers it. Apple also says to update to the latest iOS.

If your hotel Wi-Fi won't show its login page, see our guide to the Wi-Fi login page not showing.

8. If data works but crawls

You probably used up your high-speed allowance. On TravelPass, Verizon gives 5 GB per 24-hour session, then slows you to 3G speeds. T-Mobile says that once you reach the high-speed international limit, speeds drop to 256 kbps until your next bill cycle. Look for a text from your carrier about data limits. Messages will still get through, but maps get slow.

If nothing helped

Carriers alone can see your account. Apple says to ask yours whether the account is active, whether there are outages, whether the device is blocked, and whether your plan is correct.

  1. Call your carrier. Verizon's International Support Team is +1-908-559-4899. If no toll-free number is available for your country, toll charges apply on that number. T-Mobile lists +1-505-998-3793 and says to call from another line. If your own line is dead, use a partner's phone.
  2. Install a travel eSIM over Wi-Fi. Apple says you can buy one after you arrive, but you need Wi-Fi or a hotspot to set it up. Google says a prepaid eSIM can be activated during a trip. Your phone must be unlocked, so a phone still locked to your carrier won't take it. Try our phone check. Moosetrip days count from your first connection in the country, and your US number stays on as a second line. On October 30, 2026, 3 GB for 30 days costs $7 in Italy, $7.50 in Japan, and $9.50 in Thailand. It is data only, with no number.
  3. Buy a local SIM. Airports often sell them, but counters close and you may need your passport. See our guides to Narita, Istanbul Airport, and Bangkok.

An eSIM is not always the answer. If your problem was a switch or a missing pass, fix that and keep your plan. Our guide to keeping your US number abroad covers what to set up before your next trip.

Questions

Why does my phone say No Service abroad?

It isn't connected to any cellular network. Turn on airplane mode for at least 15 seconds, turn it off, and restart. Then check data roaming and choose a network by hand in your cellular settings.

Should data roaming be on or off when traveling?

On for the line you want to use for data. Off for a line you don't want to pay for. If you use a travel eSIM for data, keep it on for the eSIM and off for your US line.

Why do I have bars but no internet abroad?

The phone found a network, but data isn't reaching you. Check the data roaming switch, make sure your carrier pass or plan is active, then look for a roaming block or a VPN.

Why is my phone slow overseas?

You may have reached your high-speed limit. Verizon TravelPass gives 5 GB per 24-hour session, and T-Mobile says speeds drop to 256 kbps past its international limit.

Can I fix this without any Wi-Fi?

Partly. The switches, airplane mode, restart, and manual network choice all work offline. Carrier settings updates and installing an eSIM need Wi-Fi or a hotspot.

Sources

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