Japan eSIM Not Working? 10 Fixes (2026)

Last fact-checked: September 4, 2026.

Quick fix: If your Japan eSIM is installed but has no internet, first make sure the eSIM is turned on, select it as your mobile-data line, and enable data roaming for that eSIM if the provider requires it. Then toggle Airplane Mode for 15–30 seconds and restart the phone.

Those steps solve many arrival-day connection problems. If they do not work, use the symptom table and ten fixes below to identify whether the problem is activation, network registration, data-line selection, roaming, or APN configuration.

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Contents

First, identify what is not working
Japan eSIM not working: 10 fixes to try in order
Quick settings checklist by phone
What if the eSIM says “Activating”?
What if you have signal but no internet?
What if the connection is slow?
Should you reset network settings?
If You Need an Immediate Backup Connection
Frequently asked questions
Bottom line
Official and primary sources

First, identify what is not working

“My eSIM is not working” can describe several different problems. Match your phone to the closest symptom before changing settings.

What you see	Likely area to check	Start with
The travel eSIM does not appear in Settings	Installation or activation	Connect to reliable Wi-Fi and check the provider app or installation instructions
“SOS,” “No Service,” “Searching,” or “Emergency calls only”	Inactive line, network registration, coverage, or plan status	Turn the eSIM line on, toggle Airplane Mode, and confirm the plan is active
Signal bars appear, but websites do not load	Wrong data line, data roaming, APN, or exhausted allowance	Select the eSIM for mobile data, check roaming, then verify the APN
Only some apps fail	App, VPN, private DNS, or account issue rather than the eSIM itself	Test a normal webpage and temporarily disable connection-filtering apps
Your U.S. line is using data	Dual SIM data selection or automatic switching	Select the Japan eSIM for data and disable cellular-data switching

If you have not bought a plan yet, start with our Japan eSIM Guide. If you are unsure whether your phone is compatible or unlocked, read Will My Phone Work in Japan? before purchasing another plan.

Japan eSIM not working: 10 fixes to try in order

1. Connect to Wi-Fi and confirm the plan is active

Use airport, hotel, or another trusted Wi-Fi connection to open the provider’s app or account page. Check all of the following:

The Japan plan is active or ready to activate.
The plan covers Japan, not a different country or region.
The validity period has started and has not expired.
The plan still has data remaining.
The eSIM profile has finished installing.

Installation and plan activation are not always the same event. Some providers start validity at installation, while others begin when the eSIM first connects in the destination. Follow the rule shown for your exact plan.

2. Make sure the eSIM line is turned on

An installed eSIM can remain disabled. Turning the line off and back on also forces the phone to retry network registration.

iPhone: Go to Settings → Cellular or Mobile Service, tap the travel eSIM, and enable Turn On This Line.

Google Pixel: Go to Settings → Network & internet → SIMs, select the travel eSIM, and enable Use SIM.

Samsung Galaxy: Go to Settings → Connections → SIM manager and turn on the travel eSIM.

Apple’s eSIM troubleshooting instructions specifically recommend checking whether the line appears in Cellular settings and toggling it off and back on.

3. Select the travel eSIM for mobile data

With Dual SIM, the phone may keep using the home line even though the Japan eSIM is installed and active.

iPhone: Open Settings → Cellular → Cellular Data, then select the Japan eSIM.

Pixel: Open Settings → Network & internet → SIMs → Mobile data and select the Japan eSIM. Menu wording varies by Android version.

Galaxy: Open Settings → Connections → SIM manager → Mobile data and select the Japan eSIM.

On iPhone, consider turning off Allow Cellular Data Switching. Otherwise, the phone may use the U.S. line when the travel line has weak coverage, potentially triggering roaming charges.

4. Enable data roaming for the travel eSIM

Many travel eSIMs connect through partner networks in Japan and require data roaming to be enabled on the travel eSIM line. Ubigi and Saily both instruct users to enable mobile data and data roaming when troubleshooting their travel eSIMs.

iPhone: Go to Settings → Cellular → [travel eSIM] → Data Roaming.

Pixel: Go to Settings → Network & internet → SIMs → [travel eSIM] → Roaming.

Galaxy: Go to Settings → Connections → Mobile networks → Data roaming. On some models, confirm the correct eSIM in SIM manager first.

Do not enable roaming on your U.S. line unless your home-carrier plan covers Japan and you intend to use it. Always follow the travel eSIM provider’s exact instructions because requirements can differ.

5. Toggle Airplane Mode for 15–30 seconds

Airplane Mode disconnects the phone from the current network and makes it register again when turned off.

Turn Airplane Mode on.
Wait at least 15 seconds.
Turn Airplane Mode off.
Allow several minutes for the phone to find a Japanese partner network.

Apple, Google-device support guidance, Saily, and Ubigi all include Airplane Mode or reconnection steps in their troubleshooting advice.

6. Restart the phone

If the line and data settings are correct, restart the phone. This refreshes the modem, SIM status, and network registration. Wait a few minutes after the phone turns back on before testing.

Test with a simple webpage rather than only one app. If a webpage loads, the cellular connection works and the remaining problem may be with the app, VPN, private DNS, or account login.

7. Check automatic date, software, and carrier settings

An incorrect date or time after an international flight can interfere with network and app connections.

On iPhone:

Go to Settings → General → Date & Time and enable Set Automatically.
While connected to Wi-Fi, go to Settings → General → About. Install a carrier settings update if prompted.
Check Settings → General → Software Update for an available iOS update.

On Android: Check that automatic date and time are enabled and install current Android and system updates over reliable Wi-Fi. Google recommends using a current Android version when troubleshooting mobile connectivity.

8. Check network selection

Leave network selection on Automatic first. The phone should connect to a network supported by the eSIM provider.

If the provider’s instructions name a specific Japanese network and automatic selection fails, turn automatic selection off and choose only the network listed by that provider. Do not select a random network simply because its name appears; the eSIM may not have an agreement with it.

If a manual network does not connect, return to Automatic and contact the provider. Coverage, supported networks, and priority can differ between plans—even from the same eSIM company.

9. Verify the APN exactly

The Access Point Name, or APN, tells the phone how to route mobile data. A wrong or missing APN can produce the confusing situation where signal bars appear but the internet does not work.

Open the provider’s installation instructions and compare every APN character. Do not copy an APN from another provider or a random forum post.

Typical paths:

iPhone: Settings → Cellular → [travel eSIM] → Cellular Data Network
Pixel: Settings → Network & internet → SIMs → [travel eSIM] → Access Point Names
Galaxy: Settings → Connections → Mobile networks → Access Point Names

As one provider-specific example, Ubigi’s official support currently lists mbb as its APN. That value is for Ubigi; use the details supplied with your own plan.

10. Contact the provider before deleting the eSIM

If nothing above works, take screenshots of:

The error message or status bar
The installed eSIM line
The mobile-data selection
Data roaming
Network selection
APN settings
The plan’s active status and remaining allowance

Send them to the eSIM provider while connected to Wi-Fi. Also provide your phone model, operating-system version, location in Japan, and the time the problem began.

Do not delete the eSIM unless support tells you to. Some QR codes or activation codes can be used only once, and deleting the profile may require the provider to issue a replacement.

Quick settings checklist by phone

Setting	iPhone	Google Pixel	Samsung Galaxy
Turn on eSIM	Settings → Cellular → eSIM → Turn On This Line	Settings → Network & internet → SIMs → eSIM → Use SIM	Settings → Connections → SIM manager
Select data line	Settings → Cellular → Cellular Data	Settings → Network & internet → SIMs → Mobile data	Settings → Connections → SIM manager → Mobile data
Data roaming	Settings → Cellular → eSIM → Data Roaming	Settings → Network & internet → SIMs → eSIM → Roaming	Settings → Connections → Mobile networks → Data roaming
APN	Cellular Data Network	Access Point Names under the eSIM	Mobile networks → Access Point Names

Manufacturers and carriers may rename or move these controls. Use Settings search for terms such as SIM, mobile data, roaming, or APN if your screen differs.

What if the eSIM says “Activating”?

Connect to stable Wi-Fi and wait several minutes. Confirm that the plan is meant to activate in Japan and that the phone is unlocked. Toggle the eSIM line and Airplane Mode, then restart.

If the profile never appears in the SIM list, installation may not have completed. Do not repeatedly scan the QR code without checking the provider’s instructions; it may be a one-time code. Contact support with the exact message shown on the phone.

What if you have signal but no internet?

This usually narrows the problem to data configuration rather than installation. Check these four items:

The travel eSIM is selected for mobile data.
Data roaming is enabled for the travel eSIM when required.
The plan is active and has data remaining.
The APN exactly matches the provider’s instructions.

Then disable Wi-Fi temporarily and load a normal webpage. If the webpage works but one app does not, investigate the app, VPN, private DNS, or regional account settings separately.

What if the connection is slow?

Slow data does not necessarily mean the eSIM is configured incorrectly. Speed can change with location, building materials, underground travel, congestion, local-network coverage, and the plan’s high-speed allowance or fair-use rules.

Move outside or closer to a window.
Wait until you leave a station, tunnel, or crowded venue.
Toggle Airplane Mode and test again.
Check whether the high-speed allowance is exhausted.
Try LTE/4G if 5G repeatedly connects and drops, but only if your provider supports it.
Check the provider’s service-status or support page.

Should you reset network settings?

Use a network reset only after the safer steps above and preferably after contacting the provider. Google includes Reset mobile network settings in its Pixel troubleshooting guidance. Apple also provides network-reset options, but a reset can remove saved network configuration and require setup again.

Before resetting, save your Wi-Fi password, APN instructions, eSIM order details, and support conversation. Do not erase the eSIM as part of troubleshooting unless the provider explicitly instructs you to do so.

If You Need an Immediate Backup Connection

If the travel eSIM cannot be repaired and you need maps or messages immediately, your U.S. carrier’s Japan roaming may provide a temporary backup. Check the price and activation trigger before turning data roaming on. Background data can create a charge on some plans.

Airport or hotel Wi-Fi can give you time to contact the eSIM provider without activating carrier roaming. For choosing a replacement plan, return to our complete Japan eSIM guide. For device locks and compatibility, use Will My Phone Work in Japan?

Frequently asked questions

Why does my Japan eSIM show No Service?

The line may be disabled, the plan may not be active, the phone may not have registered with a supported Japanese network, or coverage may be temporarily unavailable. Turn the eSIM on, confirm plan status, toggle Airplane Mode, restart, and check network selection.

Should data roaming be on for a Japan travel eSIM?

Many travel eSIMs require data roaming because they use partner networks in Japan. Enable it only for the travel eSIM and follow the provider’s instructions. Keep roaming off on your home line unless your regular plan covers Japan.

Why is my home SIM using data instead?

The phone may still have the home line selected for mobile data or may be using automatic cellular-data switching. Select the travel eSIM as the data line and disable switching if you want to prevent fallback.

Can I reinstall a deleted eSIM?

It depends on the provider and activation method. Some profiles or QR codes cannot be reused. Contact the provider before deleting or attempting reinstallation.

Do I need to change the APN?

Not always. Many eSIMs configure it automatically. If you have signal but no internet, compare the APN to the provider’s official instructions and change it only when the provider specifies a value.

When should I buy another eSIM?

Do not buy a second plan until support confirms that the current plan is incompatible, expired, exhausted, or cannot be repaired. A new eSIM will not solve a carrier-locked phone or incorrect device settings.

Bottom line

When a Japan eSIM stops working, start with the lowest-risk checks: active plan, enabled line, correct mobile-data selection, and data roaming. Then reconnect with Airplane Mode, restart, verify the network and APN, and contact the provider before deleting anything.

Most importantly, keep the U.S. line and the Japan data line clearly separated. That reduces both connection mistakes and unexpected roaming charges.

Official and primary sources

Phone menus, network partners, activation rules, APN values, and support procedures can change. Follow the instructions for your exact device, operating system, provider, and plan.