Originally Posted by STS-134

I have a card from China Mobile HK called the "4G/3G Mainland China-HK Prepaid SIM Card" which provides both voice and data roaming service (although only a HK phone number). Roaming tariffs for voice calls are only HK$0.7/minute in Mainland China and HK$0.3/minute in HK. More importantly, there is a data plan you can buy that gives you 36GB of data to use over 90 days for HK$488. This card uses China Mobile in Mainland China. I also have an old China Unicom HK card (Cross Border King) in my backup phone, which provides a voice roaming tariff of HK$0.45/minute but has a much less favorable data rate of HK$118/1GB/30 days due to its age; data rates have gone down a lot in the past 7 years or so. This card uses 3HK in HK because China Unicom HK is only an MVNO but obviously uses China Unicom in Mainland China.