English 
Tiếng Việt Can your iPhone register for international roaming, how to register, and how to use international roaming on iPhone most effectively? Please refer to the following article about international roaming on iPhone.
Turning data roaming on and off on iPhone is very simple
>>> If you want to use high-speed 4G and easily contact everyone when traveling abroad, please: buy an international 4g sim
Guide to international roaming on iPhone in the simplest way
You must be wondering how to turn data roaming (international roaming) on and off on iPhone. Please follow the steps below.
Step 1:On your iPhone device, go toSettings -> selectMobile.
Step 2:In theMobile section, tapMobile Data Options.
Step 3:In this section, you just need to tapData roaming is done.So you have turned on data roaming on your iPhonethat's it. When you no longer use it, just turn it off and you're done.
>>> Use wifi freely, with unlimited data with the service: international travel wifi rental
When do you need to turn on international roaming on iPhone?
When you go abroad and want to use telecommunication services such as calling, texting, or using 3G/4G, you must turn on data roaming on iPhone and register for the international roaming service of your current mobile network. If you only register for the international roaming service but do not turn it on on your iPhone, you will not be able to use it.
Or when you buy an international SIM card, you must turn on international roaming to use it. An international SIM card is different from a regular SIM card in that you must turn on Data roaming to use it. If you forget to turn it on, you won't be able to use it even if you insert the SIM card into your iPhone.
In Vietnam, you can also turn on international roaming to choose the best network for your phone. When using a Vietnamese SIM, you will not lose money, so don't worry.
How to turn on international roaming on iPhone
The above is the guide to turn on and off international roaming on iPhone. If you are about to go abroad, remember to turn on international roaming to make calls, send texts, and use 3G/4G abroad.
