Setting up a travel eSIM takes about two minutes, but doing it in the right order — and over Wi-Fi before you leave Hong Kong — avoids the most common headaches. Here is the whole process for both iPhone and Android.
Step 1 — Check your phone supports eSIM
On iPhone, go to Settings → Mobile Data → Add eSIM. On Android, go to Settings → Network & Internet → SIMs → Add eSIM. If the option appears and your phone is carrier-unlocked, you are good to go. Most iPhones from XS onward and recent flagship Android phones support eSIM.
Step 2 — Install over Wi-Fi before you fly
After buying, the provider sends a QR code (or an "install" button in their app). Installing the eSIM needs an internet connection, so do it at home on Wi-Fi — not at the destination airport when you have no data yet. Scan the QR code via the Add eSIM screen above and label the line (e.g. "Japan trip").
Step 3 — On arrival, set it as your data line
- Turn on the travel eSIM line and turn ON data roaming for that line (this is normal for travel eSIMs — it just lets it use the local network).
- Set Mobile Data to the travel eSIM, and keep your Hong Kong SIM as the line for calls and SMS.
- Turn OFF data roaming on your Hong Kong line so it never racks up a roaming bill.
Frequently asked questions
Can I keep receiving WhatsApp and bank SMS on my HK number?
Yes. Keep your Hong Kong SIM active as the primary voice/SMS line (with its data roaming OFF). WhatsApp stays tied to your HK number over the travel eSIM’s data, and bank OTP SMS still arrive on the HK line at no roaming cost.
What if the eSIM has no signal when I arrive?
Check that data roaming is ON for the travel eSIM line, that it is selected for Mobile Data, and try toggling Airplane mode. If it still will not connect, manually select the carrier in network settings — the provider’s app usually lists the supported local networks.