If you are planning to travel to China and are wondering whether you can use your mobile phone, the short answer is probably "yes," but there are a few options you might want to consider. Some options might save you money depending on how much you plan to use your phone.
International Roaming Service
Most mobile phone providers offer customers international roaming services when you sign up for your phone contract. If you purchased a very basic plan, it may not have the option for international roaming. If that is the case, then you cannot use your mobile phone as it is to make calls.
If you do have the option for international roaming, you usually have to contact your mobile provider to turn on this feature and give them a heads up as to the countries you plan on traveling to. Some mobile phone providers may not even have roaming availability in China. If roaming in China is available, then keep in mind that roaming can be very expensive. Rates vary by country. Ask your mobile provider about the charges for phone calls, text messages, and data usage.
Next, determine how much phone usage you expect. If you plan to use your mobile phone only in an emergency, then you should be fine with this option. If you are on a business trip or you plan to make a lot of calls, texts, and go online a lot, and you do not want to rack up charges, then you have other options. You can buy an unlocked phone and purchase a SIM card locally in China or get a mobile wifi service in China to use with your phone.
Get an Unlocked Phone and SIM Card
If you can get an unlocked mobile phone, which means a phone that is not tied into a certain carrier’s network (like AT&T, Sprint, or Verizon), that means the phone will work with more than one service provider. Most phones are tied—or locked—to a certain cellular carrier. Purchasing an unlocked mobile phone smartphone can be a much easier, more reliable option than attempting to unlock a previously locked phone. You may typically pay more for the phone, sometimes several hundred dollars more, but you're not relying on anyone to unlock the phone for you.
You should be able to purchase these phones from Amazon, eBay, other online sources, and local stores.
With an unlocked phone, you can simply buy a local pre-paid SIM card in China, which is often available from shops within the airport, metro stations, hotels, and convenience stores. A SIM card, short for subscriber identity module, is a small card you slide into the phone (usually near the battery), that provides the phone with its phone number, as well as its voice and data service. The cost for a SIM card can be anywhere between RMB 100 to RMB 200 ($15 to $30) and will have minutes already included.
You can top-up your minutes, by buying phone cards usually available from convenience stores and stalls in amounts up to RMB 100. Rates are reasonable and the menu for recharging your phone is available in English and Mandarin.
Rent or Buy a Mobile Wifi Device
If you want to use your own phone or your other devices, like your laptop, but do not want to use your international roaming service, you can purchase a mobile wifi device, also called a "MiFi" device, which acts as your own portable wifi hotspot. You can buy or rent one for about $10 per day for unlimited data usage. Some plans may give you a limited amount of data to use, then you would need to top-off the wifi device with more data for a fee.
A mobile wifi device is one of the best ways to stay connected while traveling, inexpensively. To use it, you would turn international roaming off on your phone, and then log in to the mobile wifi service. Once successfully logged in, you should be able to connect to the internet, and make calls via Facetime or Skype. You can order this service, usually by renting a small handheld device, in advance of your trip or when you arrive at the airport. If you are traveling with more than one person, the hotspot is usually shareable for more than one device at a time.
Keep in mind that just because you gain online access does not mean you will have complete access. There are certain web channels and social media sites that are blocked in China, like Facebook, Gmail, Google, and YouTube, to name a few. Look into getting apps that can assist you while traveling in China.
Figuring all this out might take you a little extra time, but it most likely will save you hundreds of dollars in the long run if you plan on using your phone or the internet. If you are having trouble trying to figure out where to buy a SIM card or a mobile wifi device, or if you do not know how to enable it, most hotel staff or tour guides can help you figure it out.