ENJA
Last updated 2026-10-26
If you want your phone online the moment you land in Japan, an eSIM is the simplest way to do it. This page covers the three things that actually go wrong: whether your phone supports eSIM, when to install it, and the one setting almost everyone forgets after landing.
Open the phone app and dial *#06#. You don't need to press call — the details appear as soon as you finish typing. If you see an EID, a 32-digit number, your phone supports eSIM.
If nothing appears, look in your settings instead. On an iPhone: Settings › General › About, then scroll down to EID. On Android the wording varies by manufacturer, so try Settings › About phone, or type EID into the settings search box.
Your phone also has to be carrier-unlocked. Only the carrier you bought it from can confirm that, so if you're not sure, ask them before you travel.
We don't publish a list of supported phone models, and that's on purpose. Any such list is out of date the day it's written, and arriving in Japan with a phone that turns out not to support eSIM is a much worse outcome than spending thirty seconds on the dialer. The EID check answers the question for the phone you're actually carrying.
An eSIM is delivered online, so installing it needs a working internet connection. At home you have Wi-Fi. After you land you don't, unless you can get onto the airport Wi-Fi — and that's a bad moment to start troubleshooting.
Installing isn't the same as starting. With our Japan plans, unless a plan says otherwise, the plan starts when the eSIM first connects to a network in Japan — not when you buy it, and not when you install it. Each plan page states this, so installing at home doesn't start the clock.
The best time is the evening before you fly. You still have Wi-Fi, and you still have time to ask us if something doesn't look right.
This is the single most common reason a traveler lands with no data. The eSIM is installed correctly, but the line is switched off, or data roaming for that line is off. Nothing is broken — two switches are in the wrong position.
On an iPhone: Settings › Cellular (or Mobile Data) › tap the travel line › turn the line on, turn Data Roaming on, and set Cellular Data to that line.
On Android: Settings › Network & internet › SIMs › choose the travel line › turn it on, then turn Roaming on. The wording differs by manufacturer, but both switches are always there.
Data roaming sounds like something that costs extra. On a travel eSIM it's just the switch that lets a line issued in one country work on a network in another. You've already paid for the plan, and turning roaming on doesn't add a charge from us. Leave it on for the travel line while you're in Japan.
Plenty of travelers also turn their home line's mobile data off, so the phone can't quietly fall back to it. Whether your home carrier would charge you for that is something only they can answer.
No. The plans aren't tied to a city. What changes from plan to plan is the network it uses, how much data you get per day, whether tethering is allowed, and how many days it runs — and each plan page shows all four.
So choose by how long you're staying and how much data you want each day, rather than by city. A trip through Tokyo, Kyoto and Osaka is one eSIM, not three.
Check these in order: the line is switched on; Data Roaming is on for that line; Cellular Data is set to that line; then restart the phone. A restart after moving those switches fixes more cases than anything else.
Please do not delete the eSIM while your trip is still underway. Deleting it isn't a way to start over — if you'd rather the line stopped doing anything, switch the line off instead. Leave everything as it is and get in touch first: we can see the state of your line from our side, so we can usually tell you which of the two switches is wrong.
Online, before you travel. There's no shop to find after you arrive, and buying ahead means you install it at home on Wi-Fi rather than at the airport.
You can, but installing an eSIM needs an internet connection, so you'd have to get onto airport or hotel Wi-Fi first. Buying before you fly saves you that.
Unless a plan says otherwise, it starts when the eSIM first connects to a network in Japan, not when you buy or install it. Each plan page states this, so you can install at home safely.
Your existing line stays in your phone; a data eSIM is an extra line alongside it. Whether calls and texts on your own line still reach you while you're abroad is up to your home carrier, so please check with them.
Yes. The plans aren't city-specific, so one eSIM covers a trip that moves between cities.
Usually not. The most common cause is that the eSIM is already on the phone, but the line is switched off or data roaming for that line is off. Please do not delete it — get in touch and we'll tell you which switch to move.
