Most iPhone users pay a fixed monthly price for their data service. But that can be very different when you take your phone overseas. Whenever you're traveling to another country with your iPhone, you need to know about iPhone data roaming to make sure you don't accidentally run up a bill totaling a thousand dollars or more.

When you're using your phone to browse the web, send emails, or check social media in your home country, you're connecting to your phone company's wireless network--or networks that belong to other companies in your country that your phone carrier has agreements with.

This means that whatever network you're on in your home country, your the price you pay for you data is going to be the same.

When you take your smartphone overseas, you'll no longer be using the cellular data network belonging to the your wireless carrier. In that case, your phone will be in data roaming mode--which means you're not using your data plan and will have to pay for each megabyte of data your phone sends or receives. Phone companies charge much higher rates for people from other countries accessing their data networks. You can easily rack up a bill of hundreds or thousands of dollars by using very little data.

Here are a few ways to avoid huge iPhone data roaming charges.

Turn Off Data Roaming

This is the single most important step you can take to save yourself from big international data bills. One way to make sure you never run the risk of running up a data roaming charge is to turn off your cellular network connection completely. To turn off data roaming, do the following:

• Tap the Settings app on your homescreen
• Tap General (if you're on iOS 7, skip this step)
• Tap Cellular (on iOS 7 and higher) or Network (on iOS 6 and lower)
• Move the Data Roaming slider to Off/white.

With data roaming turned off, your phone won't be able to connect to any 4G or 3G data networks other than those in your home country. You won't be able to get online or check email (though you should still be able to text), but you also won't run up any bills.

Turn Off All Cellular Data

In iOS 4 and higher, Apple offers an even-more-ironclad way to avoid data roaming: you can now turn off all cellular data. With that setting on, the only way to connect to the Internet is via Wi-Fi. To turn off cellular data:

• Tap the Settings app
• Tap General (if you're on iOS 7, skip this step)
• Tap Cellular (on iOS 7 and higher) or Network (on iOS 6 and lower)
• Slide Cellular Data to Off/white.

This can work in conjunction with, or separately from, turning off Data Roaming. Whether you want to turn off one or both will depend on your situation, but turning this off means you can't connect to data networks even in your home country.

Control Cellular Data by App (iOS 7 and up)

In iOS 7, you can decide to let some apps use cellular data and not others. This is great if you want to use a maps app or check for a crucial email. Be warned, though: even just checking email a few times in another country can lead to a large extra bill. That said, if you want to allow some apps to use cellular data when roaming:

• Tap the Settings app
• Tap Cellular
• In the Use Cellular Data For: section, move the sliders to Off/white for the apps you don't want to use data. Any app whose slider is green will be able to use data, even roaming data.

Use Wi-Fi

When you're overseas, you may want or need to get online. To do this without incurring major data roaming costs, use the iPhone's Wi-Fi connection. For anything you need to do online--from email to web, text messages to apps--if you use Wi-Fi, you'll save yourself from these extra charges.

Monitoring Data Roaming Use

If you want to keep track of how much data you've used while roaming, check the section right above Use Cellular Data For. It's called Cellular Data Usage. The section labeled Current Period Roaming tracks your data use. If you've used roaming data in the past, though, scroll to the bottom of the screen and tap Reset Statistics before your trip so you start from zero.

Get an International Data Package

All cellphone companies that offer iPhone data service also offer international data plans. By signing up for one of these plans before you leave your home country, you can budget for Internet access on the trip and avoid exorbitant bills. You may want to use this option if you expect to need to get online regularly during your trip and don't want to be subject to finding an open Wi-Fi network.

If you choose this option, contact your cellphone company before leaving on your trip to discuss your options for international data plans. Sign up for a plan and ask them for specific instructions on using the plan and avoiding additional charges while on your trip. With this information, there shouldn't be any surprises when your bill arrives at the end of the month.

Dealing With Overseas Big Data Bills

What happens if you make a mistake, though? What if you accidentally run up a $100 or $1,000 or even $5,000 data roaming bill while overseas? You're not necessarily stuck paying that bill. Check out our tips on contesting an iPhone data roaming charge.
 
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