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The absurd present
Due to policy and hardware restrictions, smartphones sold in mainland China natively cannot install eSIMs from overseas carriers. Even for domestic carriers offering eSIM services, you still need to visit a physical store to activate them, and a single device is limited to only two eSIM profiles—a situation that feels rather absurd.
The Ingenious Solution: Removable eUICC
This is where a fascinating solution comes into play: the removable eUICC (or removable eSIM). Essentially, it takes the eSIM chip usually soldered onto a phone’s motherboard and packages it into a standard physical SIM card format. With the help of specialized tools and software to write profiles, any phone with a SIM slot can support eSIM (though it can’t write domestic eSIM profiles).
Finding the Best Setup
Currently, the best practice for using eSIMs in mainland China, in my opinion, is a Mainland China single physical SIM + eSIM device (such as the mainland iPhone 17e), paired with a removable eUICC. You can write your domestic phone numbers into the phone’s native eSIM (up to two numbers are allowed by current rules), and insert the removable eUICC into the physical SIM slot for overseas profiles. This perfectly balances domestic and international communication needs. However, the downside is that you cannot use two overseas numbers installed on the removable eUICC simultaneously, and you must tolerate the functional limitations specific to mainland iPhones.
Alternatively, using an overseas version of a single physical SIM + eSIM phone is also a solid option, but its drawbacks are exactly the opposite: you cannot use two domestic numbers at the same time.
| Solution | Domestic Number Support | Overseas Number Support | System Features | Main Drawback |
|---|---|---|---|---|
| Mainland Single SIM (w/ Removable eUICC) + eSIM | Excellent (Supports writing 2 native eSIMs) | Good (Unsupported by specific carriers like Tello) | Restricted (Mainland system features are limited) | Cannot use 2 overseas eSIMs simultaneously |
| Overseas Single SIM + eSIM | Average (Can only use physical SIMs for domestic) | Excellent (Native support for multi-profile switching) | Complete (Enjoy Apple Intelligence, etc.) | Cannot use 2 domestic numbers simultaneously |
Carrier Selection
For acquiring an overseas phone number, OneNZ from New Zealand is an outstanding choice. Not only does it support prepaid plans, making it easy to get an overseas number, but its core advantage lies in its Wi-Fi Calling feature, which has no restrictions in mainland China. This means that while in mainland China, you can enjoy New Zealand local rates directly over Wi-Fi. More importantly, OneNZ supports Wi-Fi Calling over Cellular Data. When Wi-Fi is unavailable, it can use the cellular data from the other SIM card in your phone to make calls and send texts, providing an experience nearly identical to using a local carrier. Additionally, certain eSIMs from the UK and Hong Kong offer good value for money (like giffgaff), whereas US carriers are generally more expensive.
The Magic of Home-Routed Roaming
Finally, and perhaps most importantly, you can purchase overseas eSIM roaming data to use within mainland China. Since most overseas carriers process roaming data via Home-Routed Roaming, your data traffic is routed directly back to the carrier’s data center abroad before accessing the internet. For pro users in mainland China, the implications of this are self-evident.
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