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The current situation is awkward
Because of policy and hardware restrictions, phones sold in mainland China usually cannot install eSIM profiles from overseas carriers directly. Even when a domestic carrier offers eSIM service, activation still often requires a trip to a store. On top of that, one device is generally limited to two native eSIM profiles. However you look at it, the whole thing is more cumbersome than it should be.
A removable eUICC is the practical workaround
That is why the removable eUICC matters. In simple terms, it takes the eSIM chip that would normally be soldered onto the phone’s motherboard and puts it into a physical SIM card form factor. With the right tools, you can write overseas profiles onto it and use it in almost any phone that still has a SIM slot. It does not solve every problem, and it still cannot write domestic eSIM profiles, but it gets around the biggest hardware limitation.
The setup that makes the most sense
If I had to pick one setup today, I would choose a mainland China phone with one physical SIM slot and native eSIM support, such as the mainland iPhone 17e, plus a removable eUICC. Put your domestic numbers into the phone’s native eSIM storage, up to the current two-profile limit, and use the physical SIM slot for overseas profiles on the removable eUICC. For everyday use in mainland China, this is the most balanced arrangement I have found.
The tradeoff is also clear. You cannot use two overseas profiles on the removable eUICC at the same time, and if you are on a mainland iPhone, you still have to live with the feature restrictions that come with that version.
An overseas version of a one-physical-SIM plus eSIM phone is the other reasonable choice. That setup is better for overseas profiles, but weaker if you want to keep two domestic numbers active on the same device.
| Solution | Domestic Number Support | Overseas Number Support | System Features | Main Drawback |
|---|---|---|---|---|
| Mainland single SIM + native eSIM + removable eUICC | Can keep up to 2 domestic native eSIM profiles | Works for many overseas profiles, but not every carrier | Mainland firmware, with the usual feature limits | Cannot use 2 overseas eSIMs at the same time |
| Overseas single SIM + native eSIM | Domestic numbers rely on the physical SIM side | Better native support for overseas eSIM switching | Full overseas feature set | Cannot keep 2 domestic numbers active at the same time |
Carriers worth looking at
If you want an overseas number, I would look at OneNZ first. The prepaid entry point is straightforward, and the useful part is its Wi-Fi Calling support, which works in mainland China without extra gymnastics. In practice, that means you can stay in mainland China and still use New Zealand local calling rates over Wi-Fi.
The better part is that OneNZ also supports Wi-Fi Calling over Cellular Data. When Wi-Fi is not available, the line can ride on the data connection from the other SIM in your phone. That gets surprisingly close to the feel of using a local carrier.
There are other options too. Some UK and Hong Kong eSIM products are reasonably priced, and giffgaff is a familiar example. US carriers usually cost more, so I would only go that route if you specifically need a US number.
Why home-routed roaming matters
This is the part many people actually care about. You can buy roaming data from an overseas eSIM and use it inside mainland China. In many cases, that traffic follows Home-Routed Roaming, which means the data goes back to the carrier’s network abroad before it reaches the public internet.
If you already know why that matters, you probably also know why this setup is worth the trouble. If you do not care about that routing behavior, the appeal of overseas eSIMs becomes much smaller.
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