Installing a China eSIM before you fly, step by step, with fixes for no signal

Check first: eSIM support and carrier lock

Installing a China eSIM is easy, but do it at home before you fly: you need internet to scan the QR code, and the seller's site may not open in China. First confirm your phone supports eSIM and is not locked to a carrier, because a locked phone refuses eSIMs from other providers.

• iPhone: Settings > General > About; Carrier Lock should say No SIM restrictions, and an EID should be listed.
• Android: look in Settings > Connections > SIM manager for an Add eSIM option; menu names vary by brand.
• If you bought the phone through a carrier and are still paying it off, ask whether it has been released from the lock.

Buy the plan and keep the QR code

Pick a plan using the checklist in “How to Choose a China eSIM: A Buyer's Checklist”, then save the confirmation email, the QR code and the manual install details (SM-DP+ address and activation code) offline in case you must reinstall.

Install over Wi-Fi at home

Do these steps while connected to Wi-Fi. For the general overview see “How to install an eSIM, step by step (iPhone and Android)”.

1. 1iPhone: add the eSIMGo to Settings > Cellular > Add eSIM > Use QR Code, scan the code from the email, or choose manual entry, and continue until it finishes.
2. 2Android：eSIMを追加するGo to Settings > Connections > SIM manager > Add eSIM and scan the QR code, following your brand's menu.
3. 3Label the lineName the eSIM China and the Thai SIM Thai so you never mix them up when picking a line.
4. 4eSIMをデータ回線として設定するIn the cellular menu, set Cellular Data to the China eSIM and turn off automatic data switching so the phone does not fall back to the Thai SIM.
5. 5Turn on roaming for the eSIM onlySwitch Data Roaming on for the China eSIM line and off for the Thai SIM to avoid roaming charges. Leave the Thai SIM on for calls and SMS.

中国での到着後にすること

Turn off airplane mode and wait for a Chinese network name to appear at the top of the screen. The APN is normally automatic, so enter one only if your plan provides it. Then test immediately: open the foreign apps you need, such as LINE or Google Maps, and load a web page. Do not assume every app works until you have tried it.

If there is no signal after landing

Try these in order and test after each one.

1. 端末を再起動する
2. Switch airplane mode on, wait, then off
3. Select the network manually: turn off automatic selection and pick a Chinese network from the list
4. Check that data roaming is on for the eSIM and that it is the data line

Troubleshooting table

Pre-flight checklist

• The eSIM appears in your line list, labelled China, and is switched on
• Data roaming is on for the eSIM and off for the Thai SIM
• The confirmation email, QR code and manual install details are saved offline
• Offline maps and any apps that need account sign-up are done in advance; see “Offline maps that actually work when the data runs out”
• Alipay or WeChat Pay is set up; see “Using a Credit Card in China and Linking a Card to Alipay or WeChat Pay”

While you are in China the phone runs two lines at once: the eSIM carries data and the Thai SIM receives SMS. If a Thai bank SMS does not arrive, check that the Thai SIM is still on and registered for voice and text roaming, with only its data switched off. For calls home, try an app that calls over data; see “Wi-Fi calling abroad: setting it up so it actually works”.

One more caution: a system update or a network settings reset during the trip can return roaming settings to their defaults. After any update, open the cellular menu again, and never remove the eSIM from the phone, because it usually cannot be reinstalled from the same QR code.

中国eSIMのプランを見る