Archives FAQs

How do I activate my eSIM?

A:
JB Voice eSIM activation will be processed between 10:30 AM and 6:30 PM (Japan Time).

After the activation process is completed, docomo will directly send the “Activate eSIM” notification to the device associated with the EID provided during your application.

When the “Activate eSIM” screen appears, please follow the instructions displayed on your device to complete the eSIM installation and activation.

【iPhone Example】
Open:
Settings ➡ Mobile Service (Cellular) ➡ Tap “Activate eSIM”

Then follow the on-screen instructions to complete the setup.

If the “Activate eSIM” screen does not appear automatically:

📩 Please check the eSIM activation email sent by JB Mobile.
📖 Follow the instructions in the operation manual included in the email to complete the eSIM installation and activation.

⚠️ Notes:
・Please use the device with the EID registered during your application.
・Please make sure your device is connected to Wi-Fi or mobile data to complete the eSIM activation process.

How can I update my credit card information?

Please follow the steps below to update your credit card information.

  1. Visit the JB Mobile homepage:
    https://jbmobile.jp/en/
  2. Log in to My Account.
  3. Select Stripe Billing Management from the left-side menu.
  4. Log in with your email address. You will be redirected to the Stripe page, where you can update your credit card information.

※ After the update is completed, the new credit card information will be used for future payments.

How can I delete a used Japanese eSIM?

🅰️If you accidentally delete the eSIM that is currently in use, you won’t be able to re-add it. Please be careful when performing the deletion. There is no issue if you choose not to delete it.

■ iPhone
➀Delete the Japanese eSIM 【Settings】➡【Mobile Services】➡【Select the Japanese eSIM label】➡【Delete eSIM】
②Activate the original SIM used 【Settings】➡【Mobile Services】➡【Select the original SIM label】➡ Turn on 【Enable this number】

■ Android
The operation method varies slightly depending on the brand.
※Samsung
【Settings】➡【Connections】➡【SIM card manager】➡ Select the eSIM to delete ➡ Delete
※Oppo
【Settings】➡【Mobile network】➡【eSIM】➡ Select the eSIM to delete ➡ Delete

Why am I unable to get a good signal even within the docomo service area?

【Reason 1】Even within the service area, poor signal reception can occur due to obstacles or radio interference. Try moving to a slightly different location and test again.

【Reason 2】If you are using multiple SIM cards or eSIMs at the same time, with all of them set to “on” and set to automatically switch mobile data, it may automatically switch to a SIM with poor signal reception, causing it to be unusable. It is recommended to set the mobile data to your company’s SIM and turn off the automatic switching feature. If you want to use a different SIM, manually switch the mobile data to that SIM.

Can I receive Taiwan SMS messages for free while in Japan?

Yes. You can receive Taiwan SMS messages (including verification codes) for free while in Japan.

📌 Explanation:
• Taiwan mobile numbers (such as Chunghwa Telecom / Taiwan Mobile) can still receive SMS messages while you are in Japan.
• Even without applying for international roaming, SMS reception usually works as long as the SIM card remains active.
• Receiving SMS messages generally does not incur any charges (actual conditions may vary depending on your mobile carrier).

📌 Dual SIM Settings (for both Android and iPhone):
• Keep both your original SIM (Taiwan number) and JB SIM enabled at the same time.
• For calls and SMS, we recommend keeping your original SIM (SIM1).
• Switch mobile data to the JB SIM (SIM2) for internet access.
• The same settings apply when using eSIM, allowing both SIMs to be used simultaneously.

📌 Recommendation:
• Switch mobile data to the JB SIM after arriving in Japan.
• This helps prevent accidental roaming charges from using mobile data on your original SIM.

How can I prevent my original SIM from being used for international roaming?

To avoid accidentally using your original SIM and incurring international roaming charges, please follow the settings below:

📌 Basic Settings
• Switch Mobile Data to the SIM/eSIM you use in Japan.
• Turn off the “Allow Mobile Data Switching” function.
• This prevents your device from automatically using your original SIM for internet access.

📌 SMS Information
• You can continue to receive Taiwan SMS messages normally (usually free of charge).
• SMS charges from other countries depend on the regulations of your original mobile carrier.

📌 To completely avoid roaming charges, you can turn off your original SIM:

【iOS Devices】
Settings → Cellular → Select your original SIM → Turn off “Turn On This Line”

【Android Devices】
Settings → Connections → SIM Card Manager → Select your original SIM → Turn off

📌 Recommendation
If you do not need to use your original phone number, we recommend turning off your original SIM completely to prevent any accidental roaming charges.

Can I use the SIM/eSIM again after leaving Japan and returning later?

Yes, you can.

As long as your SIM/eSIM is still within the validity period, you can continue using it when you re-enter Japan, even if you temporarily leave Japan.

📌 After returning to Japan:
• Turn on Mobile Data
• Switch Mobile Data to the JB SIM/eSIM
• Wait for your phone to reconnect to the Japanese mobile network

There is no need to apply again or reinstall the SIM/eSIM. It can be used normally as long as it remains within the validity period.

Free Wi-Fi Services at Japanese Airports

If you are unable to complete activation immediately after arriving in Japan, please connect to the airport’s free Wi-Fi first and contact our customer support. We will assist you in checking your settings and activation status.

• New Chitose Airport
https://www.new-chitose-airport.jp/ja/service/internet_fax_copy/lan/

• Hakodate Airport
https://www.airport.ne.jp/facility/wifi/

• Sendai Airport
https://www.sendai-airport.co.jp/service/wifi.html

• Narita International Airport
https://www.narita-airport.jp/jp/service/svc_33_wire

• Haneda Airport
https://tokyo-haneda.com/service/facilities/wireless_lan.html

• Chubu Centrair International Airport
https://www.centrair.jp/service/wireless-lan.html

• Kansai International Airport
https://www.kansai-airport.or.jp/service/internet/06.html

• Fukuoka Airport
https://www.fukuoka-airport.jp/service/wifi01.html

• Aso Kumamoto Airport
https://www.kumamoto-airport.co.jp/facilities/kumamoto-free-wi-fi/

• Naha Airport
https://www.naha-airport.co.jp/service/wifi/wifi-spot/

📌 Recommendation
Before departure, please save screenshots of our customer support contact information and your order details so that you can quickly receive assistance after arriving in Japan.

What should I do if my flight is delayed or canceled due to a typhoon?

📌 JB eSIM
Since the eSIM activation time can be determined by the customer, we recommend completing the eSIM issuance process after confirming that your flight will depart as scheduled.

• eSIM not yet issued: You can keep it and use it at a later time.
• Activation URL deleted: You can request a new Activation URL through our official LINE account.

📌 JB SIM Card
As long as the SIM card has not been inserted into a device and has not connected to the Japanese Docomo network, it will not be activated and can be kept for your next trip to Japan.

📌 JB Voice SIM / eSIM
Since the Japanese phone number application process begins immediately after the order is submitted, cancellations or refunds are generally not available once the application has been completed.

If you are unable to travel to Japan due to a flight cancellation, please contact us through our official LINE account. We will assist you in confirming the available options and provide further support.