Why does your phone stop reaching some sites in China?

Mainland China’s internet blocks a number of commonly used foreign services, and the fix most buyers reach for — a travel eSIM — comes with one hard rule that catches people out: it has to be installed before you land, not after.

Install your eSIM before you fly, not on arrival

Apple states this directly: an eSIM from a carrier outside mainland China can’t be installed while your device is physically in mainland China. Download and activate the profile before departure, or during a layover somewhere outside the mainland — once you’ve landed without it installed, you’re stuck without the working internet access you’d need to download it in the first place.

Why roaming data often reaches blocked services anyway

Roaming data is commonly routed back through your home carrier’s own network rather than exiting to the internet inside the visited country — a standard architecture called home routing. When that’s how your specific roaming product is configured, your traffic behaves like a connection from your home country, which is why it often reaches services blocked on the domestic Chinese internet.

This isn’t guaranteed by anything China or your operator officially promises — it’s a property of your specific roaming product, not a rule. Confirm with your own operator or eSIM provider what to expect rather than assuming every plan behaves the same way, and be sceptical of eSIM sellers who market this as a guaranteed feature — they’re selling the product they’re describing.

A local Chinese SIM is a different, domestic connection

A passport is legally valid identification for registering a Chinese SIM card — a carrier can’t legally refuse it. Registration happens in person at a carrier store or an authorised counter, with identity verification. Unlike a roaming eSIM, though, a domestic Chinese SIM sits inside the domestic internet regime directly, so it doesn’t get the same practical advantage described above. Its real value is having an actual Chinese mobile number, which some local services and apps ask for.

The fair’s own Wi-Fi doesn’t need a Chinese number at all

This is worth knowing specifically because it breaks the usual pattern: the Canton Fair’s official on-site Wi-Fi logs you in using your buyer badge number as the username and the last six digits of that same badge number as the password — no Chinese mobile number and no SMS verification required. This is specific to the fair’s own network; Chinese public Wi-Fi generally (airports, hotels, cafés) commonly still expects an SMS code sent to a +86 number, which is exactly the situation a foreign visitor’s number often can’t receive.

Data-only eSIMs and what to check before buying

Most travel eSIMs are data-only and don’t come with a phone number, meaning they can’t receive Chinese SMS verification codes — relevant if a service you need, including some public Wi-Fi outside the fair, gates access behind SMS to a +86 number. Before buying a plan, check whether it’s China-specific or also covers Hong Kong and Macau as separate roaming zones if you’re transiting through either, and confirm hotspot/tethering is allowed if you plan to share the connection.

What’s next

Set up translation apps once your connectivity is sorted, since several depend on it.