How to set up an eSIM for Japan

Install the eSIM at home over WiFi a day or two before you fly, but leave it switched off. When you land, switch your mobile data to the eSIM and turn on data roaming for it. Your home number keeps working for calls and texts if you want it to.

Before you buy

• Check your phone is unlocked and supports eSIM: will my phone work in Japan?
• Choose a plan with enough data for your trip: how much data you need
• Check when the plan’s validity starts. Ubigi and Sakura Mobile’s unlimited eSIMs start counting when you arrive in Japan, so you can install them early. Sakura Mobile’s 3GB/day eSIMs start when you install them, so install those on the day you need them.

Setting up on iPhone

1. Connect to WiFi.
2. Open the QR code or the link from your provider’s email or app.
3. Go to Settings, Cellular (or Mobile Data in some regions), then Add eSIM, and choose Use QR Code. Many providers’ apps install it for you with one tap instead.
4. When asked, label the new line something like Japan.
5. For now, keep your home line as the default for calls and data, and leave the Japan line switched off until you land.

Setting up on Android

Menu names vary by brand. On most phones:

1. Connect to WiFi.
2. Google Pixel: Settings, Network and internet, SIMs, then Add SIM or Download a SIM instead.
3. Samsung Galaxy: Settings, Connections, SIM manager, then Add eSIM.
4. Scan the QR code from your provider, or enter the activation code by hand.
5. Rename the new SIM Japan so it’s easy to spot, and leave it switched off until you land.

When you land

1. Turn on the Japan line.
2. Set it as the line for mobile data.
3. Turn on data roaming for the Japan line. Most travel eSIMs need this, even though you’re in Japan.
4. Turn off data roaming on your home line so it can’t use expensive roaming data.
5. Keep your home line on for calls and texts if you want to be reachable, or switch it off entirely to avoid roaming charges.

Messaging apps like WhatsApp keep your account and number whichever line provides the data.

If it doesn’t connect

• Toggle airplane mode on and off, or restart the phone.
• Check data roaming is on for the Japan line.
• Check the Japan line is selected for mobile data.
• Some eSIMs need an APN entered by hand. Your provider’s instructions will say if so.
• Still nothing? Contact the provider’s support, and don’t delete the eSIM. Many can only be installed once.

Questions people ask

Does eSIM work in Japan?

Yes. A travel eSIM connects to Japanese networks just like a local SIM. Compare eSIMs

Do I turn off my main line when using an eSIM?

You don’t have to. Leave it on for calls and texts if you want to be reachable on your home number, but turn off data roaming on it so it doesn’t use roaming data.

Can I still use WhatsApp with an eSIM?

Yes. WhatsApp stays linked to your home number and works over whichever line provides data.

Is a SIM or eSIM better?

If your phone supports eSIM, it’s usually easier: no tiny card to swap, and you can install it at home. A physical SIM suits phones without eSIM. Japan SIM cards

How can I get a temporary Japanese phone number?

Travel eSIMs are usually data only. See getting a Japanese phone number.