How to Set Up eSIM in Japan (Step-by-Step)

Last updated: October 14, 2026. Steps are based on Apple, Google and Samsung support pages checked on this date. Menu names vary by software version and model, and your eSIM provider’s instructions take priority where they differ.

This guide explains how to set up an eSIM in Japan, from the moment you buy a plan to the moment Google Maps loads on the train from the airport. The short version: check that your phone supports eSIM and is unlocked, read your plan’s activation rules, then install the eSIM on reliable Wi-Fi when your provider recommends. After landing in Japan, switch mobile data to the travel eSIM.

Below are step-by-step instructions for iPhone, Google Pixel and Samsung Galaxy, what to change on arrival, how to keep your home number, and a troubleshooting checklist. If you have not bought a plan yet, start with our Best eSIM for Japan comparison.

Quick Answer: How to Set Up an eSIM in Japan

1. Check your phone. It must support eSIM and be unlocked (not tied to your home carrier).
2. Buy a Japan eSIM plan and read its activation policy: when does the validity period start?
3. Install the eSIM on stable Wi-Fi before you fly if your plan’s validity rules allow it, using the QR code, the provider’s app or the manual details.
4. Leave it switched off or unused for data until you arrive, if your provider recommends that.
5. After landing, turn on the Japan eSIM, choose it as your mobile data line, and set data roaming as your provider instructs.
6. Test the connection by loading a website or a map, before you leave the airport.

Before You Start: What You Need

• An eSIM-compatible phone. Apple lists iPhone XS, XS Max, XR and later as generally compatible, but some regional versions differ. Many recent Pixel and Galaxy phones support eSIM, but availability also depends on the model and the country where it was sold. Check your exact model.
• An unlocked phone. This is a separate condition: a phone that supports eSIM but is locked to your home carrier cannot use a travel eSIM. On iPhone, go to Settings > General > About and look for No SIM Restrictions next to Carrier Lock. On Android, ask your carrier if you are not sure.
• Your eSIM details. This is usually a QR code, a provider app, or a pair of codes for manual entry (often called an SM-DP+ address and an activation code).
• Stable Wi-Fi. Downloading an eSIM needs an internet connection; home Wi-Fi is more reliable than airport Wi-Fi.
• A saved copy of your setup details. Keep the QR code or codes somewhere you can open offline, ideally on a second screen or a printout so you can scan it.
• Your plan’s start rules. Know whether the validity period starts at purchase, at installation, or on first connection in Japan.

If your phone does not support eSIM or cannot be unlocked, a travel eSIM is not an option. Our eSIM vs Pocket Wi-Fi in Japan guide covers the main alternative.

Should You Install Your Japan eSIM Before Departure?

Usually, installing at home is easier: you have reliable Wi-Fi and time to fix problems. But four dates are often confused, and they are not always the same:

• Purchase date: when you pay for the plan.
• Installation date: when the eSIM profile is downloaded to your phone.
• Activation date: when the plan is switched on, which may happen automatically or when you do it.
• Validity start: when the days on your plan start counting down.

Some providers start the validity period when the eSIM first connects to a network in Japan; others start it at installation or a set time after purchase. There is no single rule. Before you install, read the validity policy or activation policy for your exact plan and follow it.

How to Install a Japan eSIM on iPhone

These steps follow Apple’s official iPhone eSIM instructions. On many iPhones the menu is called Cellular; depending on your region and iOS version it may be called Mobile Service or Mobile Data instead.

Install with a QR code

1. Connect to Wi-Fi.
2. Open Settings and tap Cellular (or Mobile Service / Mobile Data).
3. Tap Add eSIM (on some versions, Set Up Cellular or Add Cellular Plan).
4. Tap Use QR Code and scan the code from your provider on another screen.
5. Tap Continue, then Add Cellular Plan. Enter a confirmation code if your provider gave you one.
6. Label the new line clearly, for example Japan or Travel.
7. When asked which line to use for cellular data, keep your home line for now if your plan starts on first connection in Japan, and switch when you arrive.

Alternatively, scan the code with the Camera app and tap Cellular Plan Detected.

If the QR code is on the same iPhone

Apple says that on iOS 17.4 or later, if the QR code arrives in your default email app or in a web browser, you can press and hold the QR code, then tap Add eSIM. Some providers also offer a one-tap install link (iOS 17.4 or later) or an app that installs the eSIM for you. If none of these work, use manual entry: go to Settings > Cellular > Add eSIM (or Add Cellular Plan) and choose Enter Details Manually.

How to Install a Japan eSIM on Google Pixel

This follows Google’s official Pixel eSIM instructions. Menu names can vary by Android version.

1. Connect to Wi-Fi.
2. Open Settings and tap Network & internet.
3. Tap SIMs, then Add SIM.
4. Tap Set up an eSIM.
5. Follow the on-screen instructions. When the camera opens, scan your provider’s QR code. If you cannot scan it, look for an option to enter the code manually.
6. When the download finishes, the new SIM appears under SIMs. You can tap it to rename it, for example to Japan.

To choose the data line, go to Settings > Network & internet > SIMs and, under Your primary SIMs, tap Mobile data.

Note: Pixel 10, Pixel 10 Pro and Pixel 10 Pro XL phones sold in the US are eSIM-only. Using two eSIMs at the same time requires a Pixel 7 or later and carrier support.

How to Install a Japan eSIM on Samsung Galaxy

Galaxy phones use different menus from Pixel phones. Samsung’s official US support page uses the path below. On some models and regions the labels are SIM card manager and Add mobile plan instead.

1. Connect to Wi-Fi.
2. Open Settings and tap Connections.
3. Tap SIM manager (or SIM card manager).
4. Tap Add eSIM (or Add mobile plan).
5. Tap Scan QR code (or Add using QR code) and scan your provider’s code. If you have an activation code instead, look for an option to enter it.
6. Wait for the plan to download. Samsung suggests restarting the phone afterwards to apply the eSIM profile.

To choose which SIM handles mobile data, open Settings > Connections > SIM manager. Depending on the model and region, look for Primary SIM or separate settings for calls, messages and mobile data. Select the Japan eSIM for mobile data when you arrive, following your provider’s instructions.

What to Do When You Arrive in Japan

Do this before you leave the airport, while free airport Wi-Fi is still available as a backup.

1. Turn on the Japan eSIM. Make sure the line is enabled (on iPhone, Turn On This Line; on Pixel, Use this SIM). On iOS 26 or later, your iPhone may show a Turn On Travel eSIM notification. You can choose Travel eSIM Only or Travel eSIM and Current eSIM.
2. Select it for mobile data. iPhone: Settings > Cellular > Cellular Data. Pixel: Settings > Network & internet > SIMs > Mobile data. Galaxy: Settings > Connections > SIM manager, then choose the Japan line for mobile data (the label and position vary by model).
3. Set data roaming on the Japan eSIM as your provider says. Many travel eSIMs need data roaming on for that line, because the plan connects through a partner network in Japan. Some do not. Follow your eSIM provider’s instructions for the travel line.
4. Stop your home line from using data. Keep its data roaming off unless you want to use your home plan abroad. Leave automatic data switching off too (iPhone: Allow Cellular Data Switching; Pixel: Automatic data switching) so data cannot move to your home line.
5. Test the connection. Turn off Wi-Fi, then open a website and a map app. If both load, you are connected.

If you would rather not deal with eSIM settings at all, our Internet in Japan guide covers the other ways to get online, including pocket Wi-Fi, physical SIM cards and free Wi-Fi.

How to Keep Your Home Phone Number

Most eSIM phones support dual SIM: two lines active at once. A typical setup in Japan looks like this:

• Japan eSIM: mobile data for maps, browsing and messaging apps.
• Home SIM or eSIM: kept on for receiving calls and SMS when needed, with its data roaming off.
• Messaging apps: WhatsApp, LINE and FaceTime run over the Japan eSIM’s data.
• SMS verification codes: bank and login codes go to your home number, so keep that line on if you need them.

Most travel eSIMs are data-only, with no Japanese phone number. Whether calls and SMS on your home line are charged depends on your carrier and plan, and dual SIM features vary by phone and carrier, so check both before relying on this setup.

Japan eSIM Not Working? Troubleshooting Checklist

Start with the simple checks. Do not delete the eSIM or reset your phone unless your provider tells you to.

No service or no signal

• Turn Airplane Mode on, wait about 10 seconds, then turn it off.
• Check that the Japan eSIM line is turned on.
• Restart your phone.
• Check the plan’s start date and status in your provider’s app or account.

eSIM installed but no internet

• Make sure the Japan eSIM is selected as your mobile data line.
• Make sure mobile data is turned on.
• Check the travel line’s data roaming setting against your provider’s instructions.

Wrong data SIM selected

Switch mobile data to the Japan eSIM (see the arrival steps above) and check that automatic data switching is off.

Data roaming settings

On iPhone, select the Japan line under Settings > Cellular and look for Data Roaming. On Pixel, open Settings > Network & internet > SIMs, select the Japan SIM, and look for Roaming. On Galaxy, the location differs by model and One UI version; check the Japan SIM settings or Settings > Connections > Mobile networks. Change roaming only as instructed by your travel eSIM provider, and check that you are not changing the home line by mistake.

APN configuration

Many travel eSIMs configure the APN (Access Point Name) automatically. Only change it if your provider gives you a specific APN, and copy it exactly. Depending on the device and carrier, you may find APN options under the selected cellular/SIM settings (for example, Cellular Data Network on some iPhones or Access point names on Android). The setting can be hidden or located elsewhere on some models, so consult your provider’s instructions if you cannot find it.

QR code not working

• Check you are connected to stable Wi-Fi.
• Scan from a second screen or a printout rather than your own phone.
• Try your provider’s app or the manual-entry codes instead.
• Many QR codes can only be used once. If the code was already scanned, contact your provider rather than buying a new plan.

“eSIM already installed” message

The profile is probably already on your phone. Look for it in your SIM list; it may just be turned off or unlabeled.

Slow mobile data

• Check whether you have used up a daily or total data allowance. Many plans slow down after a limit.
• Move away from basements or crowded spots and toggle Airplane Mode. If the plan has a speed limit or you have used up high-speed data, changing phone settings may not restore full speed.

Hotspot not working

Not every plan allows tethering. Check your plan’s hotspot rules, confirm the Japan eSIM is your data line, and restart the hotspot.

Still stuck? Contact your eSIM provider with your phone model, software version and a screenshot of your SIM settings.

Can You Delete or Reinstall a Travel eSIM?

You can delete an eSIM from your phone’s settings: on iPhone under Settings > Cellular (Delete eSIM), on Pixel under the SIM’s settings (Erase eSIM), and on Galaxy in SIM manager (Remove). But be careful:

• Deleting is often permanent. Many travel eSIMs cannot be reinstalled with the same QR code; it depends on the provider and plan.
• Do not delete to troubleshoot. Apple advises against erasing an eSIM as a troubleshooting step unless your carrier tells you to. Contact your provider first.
• Deleting is not cancelling. Removing the eSIM from your phone does not end a contract or a subscription. Cancel with the provider if needed.
• After your trip, deleting an expired plan is usually fine, but some providers let you top up the same eSIM later, so check first.

Common Mistakes to Avoid

1. Assuming eSIM support means the phone is unlocked. Check both.
2. Installing weeks early on a plan that starts counting at installation.
3. Waiting to install at the airport, on slow Wi-Fi with no time to fix problems.
4. Leaving your home line as the data line, which can trigger roaming charges.
5. Turning data roaming on for every line instead of just the Japan eSIM.
6. Keeping the only copy of the QR code on the same phone.
7. Deleting the eSIM to fix a problem before contacting the provider.

Frequently Asked Questions

Can I install a Japan eSIM before arriving?

Usually yes. Check your plan’s activation policy first, because some plans start counting days at installation.

Do I need Wi-Fi to install an eSIM?

You need an internet connection to download the eSIM, and stable Wi-Fi is the most reliable way to get it.

Should data roaming be on or off?

On the Japan line, follow your provider’s instructions; many travel eSIMs need it on. On your home line, keep it off unless you want to use your home carrier’s roaming.

Can I still receive SMS on my home number?

Usually, if your home line stays on. Your carrier may charge for SMS or calls abroad, so check its roaming terms.

Can I use an eSIM and a physical SIM together?

On most dual SIM phones, yes: physical SIM for calls and texts, Japan eSIM for data. Only one line can use mobile data at a time.

What if the QR code does not work?

Check your Wi-Fi, scan from a second screen, or use the provider’s app or manual codes. If the code was already used, contact your provider.

Can I use a hotspot with a Japan eSIM?

Often, if your plan allows tethering. Shared data counts toward your allowance.

Can I reinstall an eSIM after deleting it?

It depends on the provider. Many QR codes work only once, so ask before deleting a plan you still need.

Final Checklist Before You Travel

Still choosing a plan? Compare options in our Best eSIM for Japan guide. Traveling with several devices or a phone that cannot use eSIM? Read eSIM vs Pocket Wi-Fi in Japan. For every way to get online, see Internet in Japan.