China

''The People’s Republic of China is a very special country to buy a local SIM card. Although almost every mobile device is produced here in these days, buying a SIM card can be quite complicated, especially as very few people understand or speak English and you'll face some restrictions.''

Basics
This article applies only to mainland China and doesn’t refer to the 'special administration' areas of Hong Kong and Macau, where other laws are enforced and providers operate (see Hong Kong and Macau chapters).

Networks
China has three national networks: All three are state- (or “people's-“) owned and controlled. China Mobile is the largest mobile provider of the world with more than 800 Mio. customers and almost 2/3 share of the market, followed by China Unicom with 24 % and China Telecom with 14 % market share.
 * China Mobile (中国移动)
 * China Unicom (中国联通)
 * China Telecom (中国电信)

Frequencies, compatibility and coverage
* = not compatible with many GSM-devices sold outside of China

So China Mobile’s and China Unicom’s 2G (up to EDGE speed) are compatible with common GSM/2G phones (although US-models need quad-band). China Mobile’s 3G service is based on a weird Chinese-made TD-SCDMA standard, which unfortunately is not compatible with any phones from outside China. Again, if you brought your own phone from outside China, you will not be able to use 3G on China Mobile’s Network.

Only China Unicom’s 3G network is compatible with any unlocked phone that supports 2100 MHz 3G, which covers most modern smartphones in up to HSPA+ speed (max. 21.1 Mbit/s).

China Telecom uses a CDMA network which is incompatible with all GSM-phones purchased outside China. Only a few CDMA devices from the US or Asia can adapt to their frequencies (for more details see China Telecom section below).

4G/LTE started in 2013 on China Mobile as TDD-LTE on 1900, 2300 and 2500 MHz, which is now starting to be used in other countries too. Certain phones like the iPhone 6 are usable on China Mobile's 4G network. China Unicom and China Telecom were given licenses for 1800 MHz 4G FDD-LTE which are compatible with most 4G phone models worldwide and are now already on the air in most cities.

The hilarious reasons for this frequency situation are described in detail by Michael Jennings: here (His story is still accurate, but needs an update: In early 2014 China Mobile has teamed up with Apple and since then the biggest operator of the world sells the iPhone at last).

In 2014 China's regulator released MVNO licenses to different companies. Mi Mobile (小米移动 电话卡) by manufacturer Xiaomi started in September 2015 both on China Unicom and China Telecom. SIM cards are only available online to be sent to a Chinese address and registration can be made only with Chinese IDs. That's why they aren't listed (more info in Chinese here).

Coverage
China Mobile has the best coverage in the country, covering the whole nation in 2G. But you will get it only in up to EDGE speed (around a max. of 320 Kbps). This is sufficient for phone calls and texts and basic data like: maps, WAP sites, instant messaging. Not holding a phone built for the Chinese market China Mobile's 2G is pretty useless for mobile internet or VoIP calls. For this, your only choice is China Unicom on 3G/4G, which still has a reasonable coverage.

Starting up
While it has become more difficult to get a local SIM card in recent days, the process is still relatively painless (but be prepared to wait if you go the official route) There are no regulations that you have to live in the country or province. Some vendors are trying to sell mostly China Mobile SIM cards on the street. If you do this, make sure the SIM works before leaving the vendor stand. While you can skip the tedious task of registration by doing this, you will not be able to receive any support after activation.

Better go to small mobile shops or the official shops of the operators showing your passport and say “SIM Kaa” pointing at your device. Don’t expect anybody to speak English (you may be luckier if you are in a foreigner area of a big city). You may make a print copy in Chinese of the products which are featured on this site before going to the store.

The problem is recently, that most shops - even the small newsstands - only accept the machine-readable Chinese ID card. Foreign passports seem to be accepted only by the flagship stores of the providers (or at airports). While you may ask a Chinese to 'borrow' his ID card, you should know that behind the strict identification requirement is to track someone down in case of 'politically incorrect' use of the cell phone. What shops may do instead is sell you an unactivated SIM; this way, you can still enjoy the lower prices that third-party vendors are often able to get.

Start-up prices for the SIM cards can be very variable depending on the number. While a 8 in your number means good luck and an extra surcharge, a 4 in contrast is seen as bad luck and discounted. So prices are around 60 RMB for bad numbers up to 300 RMB for very lucky ones.

China's operators don't charge for new basic SIM cards (while a surcharge may be billed for a nano SIM). The minimum initial credit is 100 RMB and you have to choose a package for service, which starts at 8 RMB per month with no inclusive minutes or SMS. You can pay more (between 18 to 588 RMB per month) for a variety of combinations of minutes, SMS and data. Call costs vary depending on whether you are in or out of the province where you bought and registered the SIM card, and if you are out of province, then you also pay to receive calls unless you have a plan that includes it.

Data rates are generally low: all providers have lowered their default rate to 60 RMB per GB. This means that for data you can use their default rate. From 2015 all providers have also started to roll over unused data allowances in bundles over to the next month.

The registration can lead to some paperwork but should be done in a couple of minutes even if you don’t speak the language. Their flagship stores are very recommended especially if someone speaks English there, as he/she can help you with problems using the service. On the other side, it’s not recommended to buy a SIM card at airports, as the prices tend to be higher there, although it will be easier to find an English speaker.

Another option is to consider buying a Hong Kong-based SIM and roaming in the mainland with it. Both China Mobile and China Unicom sell dual-number SIMs in Hong Kong with very reasonably priced data packages that allow access to websites ordinarily not allowed (Great Firewall) as well as cheap voice calls and texts. Many of the Chinese issues below can be avoided by doing so (online top-up with home country credit/debit card means no one-province-only top-up voucher issues, all usage is priced at one national rate, no advertising texts) at the cost of somewhat higher prices on voice, text, and data (still well below roaming from most other countries).

Normally, all three sizes of SIM cards are available. If not, someone will cut it to size for you.

Alternatively, SIMEasy resells Tourist SIMs of China Unicom on its website at RRP, and includes free worldwide delivery in that price. SIMEasy undertakes the full legal registration including requiring passport information at booking. They are recommended if you need to know your phone number in advance and save time waiting at the airport.

Real Name Registration
A real name registration policy for mobile users in China was issued in 2010, requiring people to show their national identification card and complete a registration form when purchasing a new SIM card to activate mobile services. Started in 2013, all new mobile phone users have to register their real names in order to use any services. You might easily get a SIM card from a retail store on street, but you still have to go to the service point of the carrier for official registration and activation before using it. Though some shops will still activate your SIM card on someone else's name for a surcharge, do not expect this; due to sting operations run by local police to catch vendors doing this, you may only be able to do this if you look obviously not Chinese.

Regional organization
All three providers are organized regionally. You get a SIM card for your province/town which is associated with its number like in the US or Russia. All calls are charged equally within the province, around 0.2 RMB per minute. And you are charged the same being called and calling out. Calls outside the province will have a surcharge again inbound and outbound, international (IDD) calls can be very expensive and often not enabled at all.

This national roaming exists not only for incoming calls but for data too. On many tariffs local and national data are distinguished. So try to buy your SIM at the place you intend to use it most or buy another SIM in the next province.

Cheap foreign (IDD) calls can be made from landlines using special long-distance value cards called “IP cards” or using VoIP from your mobile if you have a stable 3G connection or a Wifi access. Be aware that an IP card costs about 20 to 25 CNY and has a credit of 100 CNY!

The regional organization of the mobile providers does mean that you have nationwide coverage, but topping up you SIM card outside of the province where you have bought it can be a formidable task. Recharge vouchers / top-up cards sold all over the country only work in the province where there are sold! This makes it very annoying for travelers to recharge their SIM cards.

So try to load enough credit in your “home” province, or you have to ask a local if he can help you. Of course online on the website of the provider or the platform of Taobao extra credit can be added from everywhere, but using a Chinese credit card only. Some travelers succeeded in topping up not by scratch cards sold all over but to look for the few agencies which provide direct / electronic top-up giving their phone number and paying in cash. Furthermore, there are reload agencies on the web, doing the top-up for a surcharge. Running out of credit is not a good idea, as your phone may be blocked for incoming calls too. This depends on the provider. China Mobile will allow you to run an overdraft. The amount varies depending on your payment history and how long you have been a customer with them. China Unicom may allow incoming calls even with a zero balance depending on your plan. If your plan allows it, you will receive a text when your balance reaches zero, notifying you of that fact. Your text messages may also be deleted if you have not stored them before in your phone.

Further particularities
You will get a lot of advertisements, which you can’t block. Ad text messages are the least annoying and can be deleted right away. But you will get calls in the middle of the night as well with only one ring. The idea is to make you call back an expensive premium number, so don't call it back. If you have a Hong Kong SIM, you may instead find banks and lenders cold-calling you advertising personal loans. These are easy to avoid by rejecting calls from numbers starting in 852. You will also get the data balance popping on your phone every time it disconnects from the network and this can be quite often.

Even if you choose to try to stick to WiFi instead of purchasing mobile data, you should know that a lot of public access points in places like Starbucks, McDonald’s or at airports need a verification code to be sent to a Chinese mobile number, which you need to provide.

Instant messaging has become an usual form of communication in China too. There WeChat is generally preferred to Whatsapp, but certain other apps like LINE and KakaoTalk are outright blocked.

Censorship
The censorship in China is so widespread and notorious that it needs to be addressed in more detail as it will certainly hamper your internet access and operations. This is often referred to as “Great Firewall of China”.

Access to lot of websites is simply blocked. Not only political, but usual sites like Facebook, Twitter or YouTube. In particular Google including Gmail, Search, Maps, etc. are blocked since it discontinued their cooperation with the Chinese authorities. Here is an updated survey of the most important websites that are inaccessible right now in China: Websites blocked in China

All social messaging (like WeChat or Whatsapp) and even text messages are screened and monitored for certain terms and can be censored. This surveillance normally applies to texts in Mandarin (Chinese) language only and English will not be filtered.

The usual way to circumvent this blocking, is to use a VPN or proxy app or software. Before travelling to China, you should download and try out some of them and possibly sign up to and familiarize yourself with one. Make sure, that they are not blocked as the Chinese government or operators (esp. China Unicom) try to sniff and kill the connection if they detect a VPN. You should also change your DNS server to a server ouside of China.
 * Here is a manual how to implement a VPN on an iPhone: how to break through the great firewall of China
 * Here are updated lists of best working VPN proxies for China: list #1list #2
 * Here is a manual how to change DNS servers and how to avoid China's DNS servers

Access to VoIP (Skype and others) is not restricted and tethering allowed on all Chinese SIM cards. This censorship is not carried out, if you are using an international SIM card (even one from Hong Kong or Macau) on roaming in China.

China Mobile (中国移动)
Normally, China Mobile should not be part of the list as it uses a very own and totally incompatible 3G version called TD-SCDMA (see frequencies above). It has the most developed LTE network too, but again it uses a very Chinese TDD-LTE which is only just starting to be used in a few other countries. For 4G 1900 MHz (band 39), 2300 MHz (band 40) and 2500 MHz (band 41, compatible with band 38) on TDD-LTE are employed.

On the other side, it’s by far the biggest operator of the world with more than 800 million customers (that’s more as twice as much as all mobile subscribers in the US on all networks together), and there are operators outside China starting to adopt TDD-LTE as well (meaning in the future more devices sold outside the country will support it). At the end of 2015 it had 250 million 4G customers alone, that's more than the next five 4G providers in the world combined. So we should make an exception.

Without doubt, it has the best network in all provinces and is your first choice for voice and text as theses rates don’t differ so much among the providers. For data you will probably get only EDGE speed up to 384 kbit/s, but often slower. So desktop websites, VPN use (see above) or VoIP are not feasible on China Mobile on most GSM-devices. The iPhone 6/6+ (except those purchased from the major carriers in America) and certain Sony phones sold in Japan (Xperia ZL2 and Z3) support the 4G used by China Mobile, resulting in a much better data experience. In addition, the iPhone 6S and 6S+ will support TD-LTE on all models as the iPad Air 2 does, so if you are getting one, you can be assured of a good data experience on China Mobile.

Easy Own and MZone
In most cities, China Mobile used to sell their prepaid cards not under its own brand name, but under other names like Easy Own (神州行= Shénzhōuxínɡ) or MZone ( 动感地带 = Dònggǎn Dìdài). From 2015 China Mobile 4G branded SIM cards are sold in the centers where LTE was launched. Prices and composition of the plans vary slightly by province.

To add value, remember value cards only work within the province: They’ll either be a scratch-off card, or a tear-off voucher, a typical value is 100 RMB for China Mobile, dial 138-0013-8000 or 138-0013-8000, press “2″ for English, then press “1#,” and enter the number printed on your voucher or card.

For cheaper international calls, you need to activate IDD prefixes. This usually requires a deposit and a visit to a China Mobile shop. Prefix 12593 costs 1 RMB per month but does not require a deposit. For IDD call prices using this prefix, see here.

You can check your balance at any time by sending an SMS with the text "ye" to the number 10086. If you have a data plan, you can send an SMS with the text "1091" to 10086, and you'll receive a reply stating how much data you've used and how much is remaining.

Data feature packs
In most provinces like Shanghai or Beijing, new subscribers are now required to pick a base plan first, which is either a MZone, EasyOwn or a new 4G global plan. MZone plans include data allowances for mobile internet and in some provinces for WiFi hotspots with the SSID of "CMCC-WEB" around China, as well as generally nationwide free incoming calls and differ between regions.

Their new 4G global plans (4G飞享套餐) all include both voice minutes and mobile data, with free incoming calls (e.g. valid in Beijing and Shanghai): These packages need to be activated in-store or online, if you know Mandarin. Other plans and packages may be available according to province. On all plans unused data rolls over to the next month since 2015.

Overuse fees are 0.29 RMB per MB and having reached 60 RMB (at slightly above 200 MB) the rest of up to 1 GB is free. Note that this makes excess data very cheap at 60 RMB per GB, only capped at 500 RMB or 15 GB. In fact, it's cheaper for using data-only to buy a small package and use excess data instead.

Roaming SIM cards from China Mobile Hong Kong
Unlike China Unicom, China Mobile has its own network in Hong Kong. However, this does not prevent them from selling their own roaming SIMs for mainland China out of Hong Kong. They come with some benefits, like bypassing the Great Firewall, skipping registration, and being able to top up with a foreign credit card. Additionally, China Mobile HK offers a bonus scheme for users, who reload online. However, their roaming SIMs are harder to find online, usually being limited to sales on eBay from third parties. If you are transiting Hong Kong on the way to China and have the time to step outside, there is a China Mobile kiosk just before security on the Departures level at HKG airport. Additionally, if you are flying into China on Cathay Pacific or Dragonair, the data-only 4G/3G SIM is sold in-flight for a HK$8 discount off face value. There are different SIM cards (only sold in/from Hong Kong):
 * The nationwide 4G/3G SIM is the 4G/3G China-HK Prepaid SIM Card which costs HK$120 and comes with HK$114 of credit valid for 180 days. Basic data rate is HK$1.5 per MB capped at HK$48 daily. The 30-day packages of 200MiB (HK$38), 1GiB (HK$118) and 2GiB (HK$198) are available.
 * Their 4G/3G China 10-day Data Prepaid SIM Card offers a data-only product for use in both HK and mainland China. This SIM is HK$148 for 1.5 GB of HK+mainland data, and can be topped up at HK$100 per extra GB of data per 10 days or used at the daily rate of HK$48 in HK or China. Take care; the initial validity period is only 10 days, so it must be topped up before expiration for additional use.

All cards state on the packaging, that they should be activated in Hong Kong. This is a suggestion, not mandatory; there is a bonus of unlimited data in HK for exactly 24 hours upon activation (you will get SMS confirmation of expiry time), but if you do not plan on going to HK first, it can be activated from within mainland China with no issue by dialing *#130# on the phone, after signal is received.

Additionally, the 4G/3G SIMs now have an FUP on the daily unlimited rate. If you use more than 1 GB in a day, China Mobile reserves the right to throttle your connection to not less than 128 kbps.

All SIMs participate in CMHK's top-up bonus scheme. The following bonuses apply for online top-ups, which can be done with a Visa or MasterCard issued from any country: For the monthly SIMs there are also the following data packs available for purchase as well as the daily option: If you go over your data pack, your internet access will be shut off. You must unsubscribe from the pack, and you can choose to resubscribe to a pack or pay the daily rate going forward (an advantage over China Unicom's HK offering).
 * HK$ 30-49 for a 5% bonus
 * HK$ 50-199 for a 15% bonus
 * HK$ 200-299 for a 20% + HK$ 10 bonus
 * >HK$ 300 for a 30% + HK$ 10 bonus
 * 200 MB for HK$ 38
 * 1 GB for HK$ 98 (HK$ 118 for 4G/3G SIMs)
 * 2.5 GB for HK$ 148 (HK$ 198 for 2 GB for 4G/3G SIMs)

From end of 2016 dual SIM cards need to registered by person in HK and this data to be transfered to mainland China unlike local HK SIM cards. For details check China Unicom HK offers below.

Do note, however, that if your phone does not support China Mobile's TDD-LTE or TD-SCDMA technology, it will not be able to access 4G or 3G, respectively in mainland China. Thus the 2G card will be the better deal due to lower pricing while still allowing access to uncensored data in rural areas the others can't reach. Their 4G/3G SIM is only an option for those who already have a 3G or 4G/LTE phone from China (or the newest high-end phones or tablets with TDD-LTE support, including some Samsung, LG, Sony and Apple devices).

More info

 * APN: cmnet (mainland China SIM) / cmhk (HK roaming SIM)
 * China Mobile Customer Service Hotline: 10086 (free, English available) / 400-120-4000 (for HK SIMs, no menus, direct line to a live person but domestic call rate will be charged)
 * Website in Mandarin for China Mobile mainland China: http://www.bj.10086.cn/index/
 * Website in English for HK China Mobile roaming in China http://www.hk.chinamobile.com/en/

China Unicom (中国联通)
China Unicom is the 2nd provider in the country and should be your preferred choice for data as it’s the only one that uses 3G UMTS up to HSPA+ speed on 2100 MHz like used in most other places in Asia, Europe or Australia (see Basics chapter).

Their coverage is not as good as China Mobile’s but still reasonable and sufficient. They started FDD-LTE on 1800 MHz in some city centers in 2014 that is commonly used for LTE in other countries too. In 2015 the focused on their 4G expansion, rather than building up more 3G coverage. Still, it offers the widest compartibility with devices from other parts of Asia, Europe and Australia.

It is recommended to buy their SIM cards in their shops or small mobile outlets with registration. As Google Maps are currently blocked in China, search on Yahoo or Bing to find the nearest store.

For cheap international calls you need to activate IDD prefixes. For IDD call prices using 17911, see here.

4G value pack (4G 套餐)
This is their universal monthly voice and data SIM plan valid nationwide in China. If your phone supports LTE 1800 MHz (band 3), try to get a 4G value pack as China Unicom's 4G network already covers most areas in mainland China. The old 3G plans plans are slowly phased out and not sold anymore. Most customers got a free upgrade for 4G in 2015. These monthly plans are offered: While it has an included monthly allowance for national data and outgoing calls and free incoming calls, it has very low overuse/default rates: 0.15 RMB per min for a call and only 60 RMB for 1 GB of data. A domestic SMS or MMS is at 0.1 RMB and an international SMS at 0.8 RMB.

Their extra data rate is worth checking more closely: For 0-100 MB extra, they charge 30 RMB, for 100-200 MB extra 60 RMB in total. Beyond, there is no further charge from 200 MB to 1 GB. This scheme is repeated for every GB used additionally resulting in an overuse fee of no more than 60 RMB per GB. Extra data is capped at 15 GB and then shut off. So the larger combo packages only make sense, if you use a lot of domestic calls too. For more data better use the cheap default rate and don’t buy a larger pack. Especially, as for all higher monthly packages, they like to see a deposit, which is inconvenient, as it pays back only slowly in the following months.

This plan is officially a “contract”, but can be terminated by just not topping up in the following month. You are supposed to give a local address. So bring a hotel card with an address along. Remember the value pack has a recurring billing cycle. You add credit to your China Unicom account and fees will be deducted, in advance, on the 1st day of each month. Keep in mind, though, that China Unicom’s billing cycle begins on the 1st day of each month regardless of the day on which you opened your account. This means that if you opened your account on May 29, you will be billed immediately a full month’s worth of charges for services between May 29 and 31, and a new billing cycle still begins on June 1.

For temporary visitors of China, 4G value packs also offer an option to switch the account to dormant mode when you leave the country. Once enabled, your account is required to stay dormant for a minimum of 3 billing months. Dormant mode gives you the option to preserve your +186 number in China while you are away from the country and reactivate your SIM immediately upon return. You dial 10010 to change these options, and customer service handles requests in English. When your account is dormant, a service fee of 5 RMB is deducted on the 1st day of each month.

China Unicom has a confusing termination policy of their SIM cards which is reflected by these 2 user comments. Make up your mind:

WARNING 23/JAN/2016: China Unicom (possibly all 3 major carriers), is getting very strict about prepaid for visitors. All 4G plans require you to cancel your plan to avoid being blacklisted. You can no longer just let your prepaid account reach zero balance and lapse on its own. If you leave the country without properly terminate your plan and account, you will not be able to re-register a new SIM/phone number on your subsequent visits to China. Termination of prepaid SIM/account require you showing up at the China Unicom corporate stores with the original ID used to registered the SIM. If you leave without properly terminating your account, the system will draw your balance through monthly plan deductions, until the balance reaches zero. The system will cancel and release your assigned phone number after 90 days after account reaches 0RMB. If you return to China at a later day and wish to register and activate another prepaid SIM/phone number, you will be required to pay the 90 days worth of monthly fee of the offending prepaid account, for the period when your account is sitting at zero balance prior to your number being released (if you did not properly terminate the account prior to leaving.) If you let your SIM/account lapse in this fashion multiple times (apparently this means 2 or more times), you will be blacklisted and not able to registered future SIMs through the normal proper channels. Cancellation of prepaid plan is only allowed if your account balance is 25 RMB or less, and it does not matter if you wish to forfeit the balance. Account termination must be done in person, and cannot be done over the phone, 10010.com website or online chat agents. I learned this process the hard way and verified that with multiple phone agents and China Unicom store associates. Recommend that recurring Western visitors don't take any risk and violate these rules as China Unicom is the only carrier supporting Western 3G/4G devices.

Update 17/AUG/2016: I bought a prepaid Unicom SIM card in Inner Mongolia province and it ran out of credit when I reached Shaanxi province. I went to a Unicom store in Xian to get more credit and they simply issued me a new SIM card rather than try to add credit to my existing account. I asked them to cancel my old SIM card, but they said that they couldn't, and that i would need to do so in Inner Mongolia. Possibly this issue of blacklisting is only region specific or it only becomes a problem when you try to get your 2nd SIM in the same region?

If you have been affected by the blacklisting and do not wish to pay, your only option to use the Unicom network going forward is to buy a SIM from Hong Kong, where registration rules don't apply.

4G Data-only / Web Surfing Pass (4G 上网卡)
This is a data-only SIM directed to modems, tablets, routers and MiFi's for heavy data volumes in 3G and 4G/LTE. You can use it in phones too, but it has no voice nor text. It is a one-off prepaid card without any obligations with 5 GB national data valid for one year sold at ¥ 600 (link) or 1,5GB for ¥ 160. There is no need for registration with these cards and they work immediately with any phone, tablet or laptop. Update 16/OCT/2016: Was today in a Unicom shop for bying a 4G Data-only Web Surfing Pass and Passport was needed.

There are other offers too depending on province. Note that some of these cards distinguish national and provincial data. You get the local bonus only in the province associated with the SIM card (see Basics chapter).

Topping up
China Unicom claims to have released a nationwide refill card. A lot of users however were not able to top it up outside the province the SIM card is attached too. So try it with a small amount (e.g. 20 RMB) first if it really works. Also if you buy the refill code online on HK website, it will not work in China.

If you fail, you can ask a Chinese friend to load it on their website with a Chinese credit card, try to find a location which is able to make a direct (electronic) top-up or use one of the internet agencies which do top ups for a surcharge like ezetop or worldremit and others.

2016 Update: "WO"
China Unicom shops (at least in Beijing) now seem to be co-branded with Unicom's subidiary "WO." If you enter a Unicom shop and ask for a SIM, they will most likely provide you with a WO card, and prices will not match the prices quoted above in this article. As of September 2016, a WO SIM at an official Unicom/WO store costs 75 RMB, and a 1GB data package (of unspecified duration) with 80 minutes of local calling costs 100 RMB. Recharging credit is easy using the automated kiosks in Unicom stores, but it is difficult to understand how to activate another data package as opposed to pay-per-use rates (which do not appear to be capped at 60 RMB/GB like the regular Unicom ones are). Balances can be checked by texting "tycl" to 10010 (and then translating from Chinese).

Roaming SIM cards from China Unicom Hong Kong
China Unicom also operates a MVNO in Hong Kong. They sell dual-number roaming SIMs that work in both Hong Kong and the Chinese mainland. One reason to get a SIM in Hong Kong instead of mainland China is because a China Unicom HK SIM will pass all data through Hong Kong, allowing through the “Great Firewall of China” (see Basics). Another reason is to be able to add money using a foreign Visa/MasterCard or PayPal at http://www.cugstore.com/tp/, which you can't do with a mainland SIM. This also conveniently avoids the issue of out-of-province top-ups since it's all done online. You can skip registration for these cards too.

Biggest benefit: The Unicom HK website is now in English, making the purchase and top-up process much easier than with mainland-based service.

Caution: Only use mainland recharge vouchers as a last resort with a Hong Kong SIM. Vouchers from any province will work, but the HKD conversion happens at a 1:1 rate, meaning you lose over HK$ 20 per 100 RMB topped up.

However these cards need to be purchased before travelling to mainland China in Hong Kong or online out of Hong Kong as they are not available in mainland China.

Their “Cross Border King Dual Prepaid SIM” is sold officially for HK$ 120  but often discounted to HK$ 70 with HK$ 66 credit. Default data is HK$ 2 per MB for Hong Kong and China and a monthly administration fee of HK$ 6 is debited. Voice costs HK$0.45/minute in Guangdong and HK$0.60/minute elsewhere. Three data passes can be bought: Days are counted midnight to midnight in Hong Kong time, passes don’t renew automatically and overuse is charged by the default rate.
 * monthly: 100 MB pass for HK$ 35 - activation: *118*431#
 * 1 day: 300 MB for HK$ 38 - activation: *118*441#
 * 7 days: 500 MB for HK$ 78 - activation: *118*500#

Warning: The daily and monthly passes can NOT be changed after activation. Each extra MB costs HK$ 2, which is rather costly. Even though the pamphlet lists *118*430# as cancel code (for the monthly pass), it doesn't work. It was confirmed by calling the operator. The best way to get the most reasonable rate is to charge extra HK$ right after you buy the SIM card, then activate the data pass (1-day or 7-day).

The 7-day pass is the only one that can be renewed early if you run out before the pass expires. You will receive a text, possibly in Chinese, prompting you to reply "500" (no quotes) to it to renew the package. Make sure you have $78 in your account, then reply to renew.

They have a very similar product called “Cross Border King Dual Extra Prepaid SIM” for HK$ 138, often discounted to HK$ 100 with HK$ 80 credit. This card may be better value, as incoming calls are free, calls in all provinces are only HK$ 0.39/minute, default data is HK$ 0.80 per MB, and these packages are available: The 300MB and 500MB packages are also applicable for Macau and Taiwan, while the 1GB package is only good in HK and mainland China.
 * 7 days: 300 MB for HK$ 48 - activation: *118*448#
 * 30 days: 500 MB for HK$ 68 - activation: *118*468#
 * 30 days: 1GB for HK$118 - activation: *118*504#

However, this card includes an increased monthly administration fee of HK$ 18 per month. If you activate after the 15th, the administrative fee is HK$ 9 for the remainder of that month.

When you have exhausted the data in the package, you will get a text message informing you. You can then start a new package if you have sufficient credit in your account. The data service is only 3G, but the coverage is good.

Finally, they have a data-only SIM for Hong Kong and China, sold for HK$ 150, often discounted to HK$ 108 with 1 GB of data in Hong Kong (on 3 network) or China in 7 days. You can recharge by credit card or HK$ 100 vouchers available in 7-Eleven stores in HK for another 1 GB within 7 days at HK$ 100.

Unlike regular HK SIM cards starting December 2016 SIM cards with dual number need to be activated with a copy of passport and this has to be done in HK in person: [http://see see here] The HK regulator has issued a consumer alert about dual SIMs. For compliance with regulations in the mainland, HK operators need to collect personal information and to obtain their consent to transfer the information to mobile operators and authorities in the mainland in order to enable them to continue the use of the mainland mobile numbers. If subscribers do not provide the required information or give their consent about transfer of such information, use of the mainland mobile numbers may be suspended.

More info

 * APN: 3gnet for all SIMs
 * Customer Service (in English available): 10010 for mainland SIMs or 13068400177 for Hong Kong SIMs
 * Website in Mandarin only: http://3g.10010.com for mainland SIMs or http://www.cugstore.com/usa/ (now in English) for Hong Kong SIMs.

Compatibility
China Telecom uses CDMA (and thus EVDO for 3G) like (Sprint and Verizon) in the US and in a few other Asian countries, which is incompatible with GSM-devices (see above). Their reliance on R-UIMs instead of the traditional North American method of storing programming data in the phone means that from overseas, only a select few unlockable devices from the Japanese CDMA provider “au”, some Verizon phones from the US, and the latest generation of Verizon/Sprint-models with LTE and SIM/R-UIM slots are capable of using their network for voice and text. Older Verizon and most Sprint phones without card slots can be made to function on the network, however, this method is no longer available to visitors (purchasing mobile phone service online now requires real-time identity verification using a system that only functions with Chinese ID).

Furthermore, China Telecom has the smallest network with a market share of around 14 %. As a consequence, it has lower-priced plans and a long-standing practice of offering significant amounts of bonus credit with new subscriptions to attract more customers. For customers with compatible phones or tablets, China Telecom will most likely be a better deal. Do note, however, that only Verizon and unlockable au LTE-capable CDMA devices will completely function upon insertion of a China Telecom R-UIM; older Android handsets will only function with voice and text without additional software modification. iPhone 5 and newer from Verizon and Nexus 5X/6P and iPhone 6 and newer from all carriers will also function with China Telecom without modification. iPad Air and newer will also function with China Telecom for data only.

With these rates being much lower than on the two major players, you might also think of getting a CDMA USB-dongle or MiFi for data which is available for a few hundred RMBs, if you stay for longer in China. If you do not plan on leaving a major city and only need data, China Telecom runs an LTE network that is compatible with most devices sold overseas, even if they were made for GSM carriers.

Start up and availability
Overseas visitors requiring Chinese prepaid SIM cards will need to show a passport only when buying at an official China Telecom location. Purchasing a SIM from a smaller shop officially requires the buyer to take the SIM to a store for activation if they do not posess a Chinese citizen ID card; the store may or may not be willing to activate it for you with a staff-provided ID card.

Deposit required varies from 50 to 900 RMB depending on desired plan but monthly charges can be taken from this. Be careful; the deposit with China Telecom is not refundable. However, the plan will typically leave little credit after the monthly plan charge is deducted.

Data feature packs
4G data plans that are sold by usage typically don't sell data on a rolling monthly basis, but instead a certain amount of data good for a set amount of time, allowing for more flexible usage. Single-month SIMs are available, but not easy to find, and most third-party vendors will want to push multi-month packs on you instead. Unfortunately, there is no movement to make single-month cards more widely available. Product link: http://www.189.cn/products/0609326550.html. These SIM cards are nationwide data-only and on 2G (CDMA), 3G (EVDO) and 4G (LTE) too and on their (unlimited) Wi-Fi, where available. Overuse fees are at a low 60 RMB per GB. The first 100 MB is charged at 0.3 RMB/MB, 100 MB - 500 MB another 30 RMB and no charge from 500 MB to 1 GB. This is repeated for every additional GB, capped at 600 RMB or 15 GB. For other products, check their website.

Asking for 'data only SIM-cards' may confuse the Telecom sales people. Instead ask for "internet card" (liu liang ka) or print out the offer above. You need to provide your passport and a phone number (ideally for your hotel) and the process can be more time consuming than expected.

More info

 * APN: ctnet
 * Customer Hotline (in English available, if you are lucky): 10000
 * Website in Mandarin: http://www.189.cn

3G SOLUTIONS
http://www.3gsolutions.com.cn

This is a reputable company which markets the products of China Unicom abroad for years. They send 4G/3G SIM cards to any place in China and abroad, rent SIM cards and pocket WiFis and do top-ups too.

It might be of an extra value for somebody to have a SIM card before arrival or a 100% English-speaking support, but you must be aware that their products will come at surcharge of some percentages.

For more info check their website and compare with the prices mentioned above for China Unicom.

UCOM Mobile
http://www.ucomobile.com

They provide portable Wi-Fi rental & prepaid data SIM sale in China mainland. They offer unlimited data plans and pay-as-you-go plans for short-term visitor. You might place order online and arrange pickup/drop-off in your hotel. Furthermore, they offer unlimited VPN service is available for surfing to access blocked site (Google, Facebook etc.) from China.