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.

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.

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.

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.

📌 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.

① When You Receive Your SIM Card

Simply insert the SIM card into your phone to start using:
📞 Voice Calls
📨 SMS

✔ Wi-Fi and Mobile Data settings do not affect voice or SMS service.

② Do NOT Configure APN Outside Japan (Important)

❌ iPhone: No configuration profile is required.
❌ Android: No APN setup is required.

📍 APN settings are only required when using mobile data (1–50GB) in Japan.

③ Dual SIM Settings

If your phone has two SIM cards:

✔ Select the SIM you want to use for mobile data.
✔ It is recommended to turn off Automatic Mobile Data Switching.

👉 This prevents your phone from switching to the SIM that cannot access the internet.

④ If the SIM Doesn’t Work

Please try the following first:

1️⃣ Update your phone to the latest system version (VoLTE support is required).
2️⃣ Remove any APN settings (do not configure APN outside Japan).
3️⃣ Turn Airplane Mode on and off to reconnect to the network.
4️⃣ Restart your phone.

⑤ Still Not Working?

👉 Please test the SIM card in another phone (your spare phone or a friend’s phone).

✔ Works in another phone → The issue is with your phone settings.
✔ Doesn’t work in any phone → The SIM card may be defective (we can arrange a replacement).
✔ If the issue is due to device compatibility → We can assist with a return or refund.

🅰️After updating to iOS 17, there may occasionally be an issue where the signal bars do not display the signal strength, but this does not affect reception. You can try the following methods:

• Restart the iPhone
• Toggle Airplane Mode on and off
• Turn mobile data off and on
• Check for software updates

🅰️ Since JB voice SIM does not offer an online real-time data usage query service, please use the statistics function on your smartphone or tablet device. Please refer to the “How to check your mobile data usage” in the common questions of the JB series.

📴 3G services have been discontinued, and international roaming voice calls now require VoLTE (4G voice calling) support.

⚠️ If your phone does not support VoLTE or VoLTE is not enabled, you may experience issues such as:

• Unable to make calls
• Unable to receive calls
• Problems using voice calls while roaming overseas

Before traveling abroad, please confirm that your device supports VoLTE and that the feature is enabled to ensure normal voice call service while roaming.