Q: When does the validity period start counting?

After purchase and receiving the activation URL, the validity period does not start counting immediately . You can open the URL to check the activation information in advance. After pressing the “Issue” button and generating the eSIM activation QR code, if you do not install or use the eSIM, the validity period will automatically start counting from the 3rd day after the QR code is issued . After adding the eSIM to your smartphone, the validity period will not start while you are outside Japan . The validity period begins when you arrive in Japan and your device connects to a Japanese mobile network. ※ However, if you have not arrived in Japan by the 3rd day after the QR code is issued, the validity period will start automatically.

Q: Use Your Taiwan Wi-Fi Calling Service in Japan

Taiwan's major mobile carriers provide Wi-Fi Calling services. ➡ While you are in Japan, Wi-Fi Calling is treated as if you were using your phone in Taiwan. 📲 Receiving calls and SMS: Free 📲 Making calls and sending SMS: Charged at your Taiwan domestic rates 📶 Requirements ・Your phone is connected to Wi-Fi . ・ Wi-Fi Calling is enabled on your phone (please refer to the attached guide). ・Your Taiwan SIM card is active. (No international roaming subscription is required, so you don't need to worry about additional roaming charges.) 📞 How to Make Calls Calling a Taiwan number ➡ Dial the Taiwan phone number directly without adding the country code. Calling a Japan number ➡ Make an international call. (Example: 009-81-... ) 🌟 Benefits ・No need to enable international roaming. ・You can make and receive calls over Wi-Fi even in areas with poor mobile signal, such as indoors. ・The person you're calling will not know that you're overseas. ・You can also receive SMS verification codes while abroad.

Question 1

When does the validity period start counting?

meng · Accepted Answer

After purchase and receiving the activation URL, the validity period does not start counting immediately. You can open the URL to check the activation information in advance.
After pressing the “Issue” button and generating the eSIM activation QR code, if you do not install or use the eSIM, the validity period will automatically start counting from the 3rd day after the QR code is issued.
After adding the eSIM to your smartphone, the validity period will not start while you are outside Japan. The validity period begins when you arrive in Japan and your device connects to a Japanese mobile network.
※ However, if you have not arrived in Japan by the 3rd day after the QR code is issued, the validity period will start automatically.

Question 2

Can I receive Taiwan calls and SMS for free while in Japan?

meng · Accepted Answer

Yes, you can use this service if the following conditions are met:

✅ Your smartphone is connected to Wi-Fi
✅ The Wi-Fi Calling function is enabled
✅ You are using a supported device (iPhone / Android)
✅ Your SIM card remains active (not suspended or cancelled)

💰 Charges (Important)
Wi-Fi Calling is treated as if you are using the service in Taiwan.

📞 Making calls
・Calling a Taiwan number → Taiwan domestic call charges
・Calling a Taiwan mobile number → Taiwan domestic rates
・Calling overseas (e.g., Japan) → International call charges

👉 No international roaming charges will apply

📲 Receiving calls
・Receiving calls from Taiwan → Free (same as receiving calls in Taiwan)

🌟 Benefits
・Good call quality when the Wi-Fi connection is stable
・You can make and receive calls without enabling international roaming

Question 3

Use Your Taiwan Wi-Fi Calling Service in Japan

meng · Accepted Answer

Taiwan's major mobile carriers provide Wi-Fi Calling services.

➡ While you are in Japan, Wi-Fi Calling is treated as if you were using your phone in Taiwan.

📲 Receiving calls and SMS: Free

📲 Making calls and sending SMS: Charged at your Taiwan domestic rates

📶 Requirements

・Your phone is connected to Wi-Fi.

・Wi-Fi Calling is enabled on your phone (please refer to the attached guide).

・Your Taiwan SIM card is active.
(No international roaming subscription is required, so you don't need to worry about additional roaming charges.)

📞 How to Make Calls

Calling a Taiwan number

➡ Dial the Taiwan phone number directly without adding the country code.

Calling a Japan number

➡ Make an international call.
(Example: 009-81-...)

🌟 Benefits

・No need to enable international roaming.

・You can make and receive calls over Wi-Fi even in areas with poor mobile signal, such as indoors.

・The person you're calling will not know that you're overseas.

・You can also receive SMS verification codes while abroad.

Question 4

Any SIM restrictions？

莊郁如 · Accepted Answer

【 iOS Device】

「settings」➔「General」➔「About」➔「Carrier Lock」 ➔No SIM restrictions

【 Android Device】

You cannot determine this directly from the mobile phone. Please check with the place of purchase or the carrier you have a contract with.
SIM lock regulations vary by country. In Taiwan, most phones are not SIM-locked.Devices purchased in countries like Japan or the United States are more likely to have SIM lock issues.
📢If you have used SIM cards from different countries or carriers, the device is likely not SIM-locked.

Question 5

How many GB are needed about 1 day？

莊郁如 · Accepted Answer

Question 6

How long can 1GB last for internet usage？

莊郁如 · Accepted Answer

Question 7

Is the speed of a physical SIM card faster than an eSIM?

莊郁如 · Accepted Answer

The signal strength is mainly affected by the telecommunications company’s network infrastructure. The factors that influence the signal strength are as follows:

The distance to the base station
Presence of obstacles
Presence of signal interference
Antenna performance
Frequency band Since our company’s eSIM and SIM cards are products from Japan’s local docomo telecom company, using the same signal, the speed of our eSIM and SIM cards are the same. As for other international roaming eSIMs, there may be cases where roaming is done through smaller telecom companies, leading to significant differences in speed and coverage.

Question 8

docomo’s System Maintenance Time

莊郁如 · Accepted Answer

Regular maintenance hours (Japan Time)

Every Tuesday from 10:00 PM to Wednesday 9:00 AM

■eSIM
During the system maintenance period, issuing eSIM activation QR codes will not be possible.
If the “Issue” button has already been pressed, the status will remain as “Pending.”
You may exit the screen and return later via the link to check the issuance result.
If the activation code has already been issued, you can still proceed with “Add eSIM” and begin using the service, even during maintenance.

■SIM Card
Inserting a physical SIM card into a smartphone or other device during the maintenance period may result in no response.
However, there is no need to worry — the system will automatically complete the activation process in order once maintenance is finished.
SIM cards that are already in use will not be affected.

■Voice SIM Card
Voice SIM cards are pre-activated before delivery and are therefore not affected by system maintenance.

Temporary Maintenance hours (Japan Time)

① Sep. 24, 2025, 10:00 PM ～ Sep. 25, 2025, 9:00 AM

■Functions Temporarily Unavailable

New line activation for physical SIMs will not be available
Activation codes for eSIMs will not be issued

■Notes

Physical SIMs that request activation during the maintenance will be activated sequentially after the maintenance ends.
Activation codes requested during the maintenance will be issued sequentially after the maintenance ends.
SIM cards that have already been activated and are in use will not be affected.
Activation codes that have already been issued can still be installed and used during the maintenance period.

Question 9

Why is it better to choose docomo products for prepaid cards?

莊郁如 · Accepted Answer

🅰️The prepaid card uses a 4G/LTE mobile network, and docomo has the most base stations in Japan, offering the widest coverage. Please refer to the comparison table below.
When you go to areas outside major cities in Japan, you will notice a significant difference.

Question 10

Why is the signal bar not showing on my iPhone?

莊郁如 · Accepted Answer

🅰️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

Question 11

How can I check if the area I want to use has signal?

莊郁如 · Accepted Answer

🅰️Our company uses the services of Japan’s largest mobile communications company, docomo, which has the widest coverage.
You can use the following website to enter an address and check the 4G/LTE service coverage:
👉docomo Mobile Network Service Area Search

Question 12

Can the QR for activating eSIM be issued in advance overseas?

莊郁如 · Accepted Answer

🅰️Yes, it can be done.
As long as you’re in a place with internet access, you can issue it. Since the issuance takes about 15 minutes, if you’re concerned about not being able to connect to the free Wi-Fi at the airport or other places in Japan, it’s recommended to issue the QR code in advance in Taiwan.

📢【Important Note】Once the QR code is issued, even if it’s not used, the validity period will automatically start counting from the 3rd day after issuance. Therefore, please make sure your travel plans are confirmed before issuing it, and do so before your departure. If there are any changes to your itinerary, you can keep the QR code unused for later use, as long as it hasn’t been issued.
*The time reference is based on Japan Standard Time.

Question 13

Can I add eSIM while outside Japan?

莊郁如 · Accepted Answer

🅰️Yes, it can be done.
When adding eSIM outside Japan, it will not be fully activated. The screen will stay on “Activating…”.
Once you arrive in Japan and receive the docomo signal, it will automatically activate successfully.

Question 14

Why can’t the eSIM be fully activated while outside of Japan?

莊郁如 · Accepted Answer

🅰️Our eSIM uses the local docomo mobile network in Japan, so it can only receive the signal after entering Japan. Once the signal is received, it will automatically activate immediately.

【Note】Most of the eSIMs currently available on the market are international roaming eSIMs sold by telecom companies from various countries in Taiwan. This is why they can be set up before traveling abroad, and you need to turn off roaming while outside Japan and enable international roaming after arriving in Japan. Since our eSIM is a local product for Japan, you do not need to enable roaming.

Question 15

What should I do if I cannot scan the QR code on my own phone after issuing it from my phone?

莊郁如 · Accepted Answer

🅰️【【Settings】➡【Mobile Services】➡【Add eSIM】➡【Use Mobile Barcode】➡ Scan the QR Code

➀Take a screenshot of the QR code and send it to another device so you can scan it with your phone.

②Print the QR code so you can scan it with your phone.

③Select【Manual Input of Details】and copy the【SM-DP+ address】and【Activation Code】from the【eSIM Activation URL】. For detailed instructions, please refer to the 👉 Instructions Before Use & Set up the APN

Question 16

Why can’t my iPhone scan QR codes?

莊郁如 · Accepted Answer

🅰️iPhone
【Settings】 ➡【Camera】 ➡【Scan QR Codes】 ➡ ON

Question 17

How can I check the data usage and validity period of my eSIM?

莊郁如 · Accepted Answer

🅰️After purchasing, the 【eSIM Activation URL】 sent to the customer from biz@jbrg.jp can be used not only to issue the activation QR code but also to check online the data usage and validity period, among other information.

Question 18

Once the purchased high-speed data is used up, will I no longer be able to access the internet?

莊郁如 · Accepted Answer

🅰️You will not be disconnected within the validity period and can use the internet with a speed of 200kbps indefinitely.
High-speed data can be added as needed. 👉【eSIM/SIM】Recharge

Question 19

Is it possible to extend the validity period of the eSIM or add more data?

莊郁如 · Accepted Answer

🅰️All eSIMs can have their validity period extended or additional high-speed data added.

You can top up or extend within the validity period.
Remaining data and newly added data are treated the same; there is no usage priority between the two.
There is no limit to the number of top-ups or extensions.
If you top up within 7 days after the expiration date, the data balance will be reset to zero, but you can continue using the original eSIM or SIM card.
The extension period is calculated from the 2nd day after the original expiration date, which is considered the first day of the new validity period.
After purchase, in addition to receiving an email with an electronic receipt, you will also receive a separate activation notice from our company via biz@jbrg.jp.
You may request a cancellation before receiving the activation notice. However, a 5% processing fee will be deducted to cover credit card company fees.
If you apply for an extension after 6:00 PM on the last day of validity, please contact customer service for confirmation before making the purchase to avoid delays in processing.
After the initial validity period ends, the online inquiry system [eSIM Activation URL] will no longer reflect the extended validity or remaining data. Please use your mobile device’s data usage statistics instead.
All JBeSIM plans are eligible for top-up and extension. JB SIM cards with data capacity (X-GB) can be topped up, while time-based plans (6/8/16/31 unlimited) cannot be extended.

Question 20

Can I Use Personal Hotspot for Free?

莊郁如 · Accepted Answer

🅰️ Yes! No additional application or activation is required. 😊

All JB SIM and JB eSIM products support Personal Hotspot at no extra charge.

⚠️ Before using Personal Hotspot, you must configure the Personal Hotspot APN settings. Otherwise, you won't be able to share your mobile data connection with other devices.

Question 21

How to Configure APN for Personal Hotspot

莊郁如 · Accepted Answer

🅰️ To share your mobile data connection with a computer, tablet, or other devices using Personal Hotspot, you must first configure the APN settings.

🍎 iPhone (iOS)

📱 Single SIM

Settings ➡ Cellular ➡ Cellular Data Network

Enter the following information under both Cellular Data and Personal Hotspot:

✔ APN
✔ Username
✔ Password

📱 Dual SIM / Multiple SIMs

Settings ➡ Cellular ➡ Select the SIM you want to configure ➡ Cellular Data Network

Enter the following information under both Cellular Data and Personal Hotspot:

✔ APN
✔ Username
✔ Password

⚠️ Each SIM has its own APN settings. Be sure to select the correct SIM before making any changes.

⚠️ In most cases, you should configure the SIM currently selected for Cellular Data.

✅ After the APN is configured

A Personal Hotspot option will appear in Settings.

Turn on:

✔ Allow Others to Join

We also recommend changing your Wi-Fi password before sharing your connection.

📌 To check your Wi-Fi (device) name:

Settings ➡ General ➡ About ➡ Name

🤖 Android

For Android devices, whether you are using an eSIM or a physical SIM card, you must configure the APN before you can access mobile data or use the Personal Hotspot feature.

Using Samsung as an example:

Settings ➡ Connections ➡ Mobile Networks ➡ Access Point Names (APN) ➡ Tap ＋ (Add)

Enter the APN information provided with your SIM:

✔ APN
✔ Username
✔ Password

Save the settings when finished. You can then use mobile data and the Personal Hotspot feature.

⚠️ The menu layout may vary depending on the Android brand and model, but the setup process is generally the same.

Question 22

How do I turn on Personal Hotspot or change the password?

莊郁如 · Accepted Answer

🍎 iPhone (iOS)

📌 Turn on Personal Hotspot:
【Settings】 ➡ 【Personal Hotspot】 ➡ Turn on 【Allow Others to Join】
You can then share your mobile data connection with other devices.

📌 Change Wi-Fi Password:
【Settings】 ➡ 【Personal Hotspot】 ➡ 【Wi-Fi Password】
Enter a new password and save the settings.

📌 View or Change Wi-Fi Name:
【Settings】 ➡ 【General】 ➡ 【About】 ➡ 【Name】

This device name will be displayed as the Wi-Fi hotspot name when other devices search for available networks.

🤖 Android

※ The operation interface may vary depending on the brand and model. The following example uses Samsung A55.

📌 Turn on Personal Hotspot:
【Settings】 ➡ 【Connections】 ➡ 【Mobile Hotspot and Tethering】 ➡ Turn on 【Mobile Hotspot】

You can then share your mobile data connection with other devices.

📌 Change Wi-Fi Name or Password:
【Settings】 ➡ 【Connections】 ➡ 【Mobile Hotspot and Tethering】 ➡ 【Mobile Hotspot】

📌 Tap 【Network Name】 or 【Password】
to enter the settings page and modify the hotspot name and password.

Question 23

I have completed the settings according to the instructions, but why can I still not use the Personal Hotspot function?

莊郁如 · Accepted Answer

🅰️ Please check the following items first:

① Confirm that the APN is set for the correct SIM/eSIM

If your phone uses multiple SIM cards or eSIMs at the same time, the most common issue is that the APN was set for the wrong SIM card.

Please confirm that the SIM/eSIM currently used for Mobile Data is the same SIM/eSIM where the APN settings were entered.

② Restart your device after completing the settings

After completing the APN settings, please restart your phone once and test the Personal Hotspot function again.

③ Recheck the APN information

Please carefully verify the following information:

✔ APN
✔ Username
✔ Password

Make sure all settings exactly match the information provided in the instruction manual.

⚠️ Important Notes

Due to the wide variety of smartphone brands, models, and operating system versions, the settings screens may differ depending on the device. Therefore, we cannot guarantee that the Personal Hotspot function will work on every device.

However, as of now, we have not received any cases where the Personal Hotspot function could not be used due to an issue with the JB SIM/eSIM itself.

Question 24

Can I set up the Personal Hotspot APN before arriving in Japan?

莊郁如 · Accepted Answer

🅰️ Yes, you can.
We recommend completing the APN settings before departure, so you can use the Personal Hotspot function immediately after arriving in Japan.

⚠️ However, our SIM/eSIM products use Japanese local mobile networks and are not international roaming products. Therefore, they cannot connect to the Japanese Docomo network while you are outside Japan. Even if the APN settings have been completed, you will not be able to confirm whether the settings are successful or test the Personal Hotspot function overseas.

📌 In short:
✔ You can set up the APN before traveling.
✔ You can use it after arriving in Japan.
❌ You cannot test whether the APN settings are working while outside Japan.

This is a normal situation. Please test the connection after arriving in Japan and connecting to the mobile network.

Question 25

When using multiple SIM cards or eSIMs at the same time, do I need to set a separate Personal Hotspot name or password for each one?

莊郁如 · Accepted Answer

🅰️ No, you do not.

The Personal Hotspot name (Wi-Fi name) and password are based on the smartphone device settings, not the SIM card settings.

Therefore, regardless of how many SIM cards or eSIMs are installed on your phone:

✔ The Personal Hotspot name and password are shared device settings and do not need to be configured separately.

⚠️ The setting that needs to be configured individually for each SIM card or eSIM is the Personal Hotspot APN.

Question 26

【iPhone】 How to Save Mobile Data Usage

莊郁如 · Accepted Answer

◆ Turn off background app refresh using mobile data
Go to “Settings” → “General” → “Background App Refresh”
Since most apps don’t need real-time updates, it’s recommended to set this to “Wi-Fi” so mobile data isn’t used.

◆ Turn off “Wi-Fi Assist”
Go to “Settings” → “Cellular” → Turn off “Wi-Fi Assist.” When Wi-Fi connection is poor, the system won’t automatically use mobile data.

◆ Turn off mobile data for iCloud backup
Go to “Settings” → “Cellular” → “iCloud Backup,” and turn it off so mobile data won’t be used for automatic iCloud backups.

Question 27

【YouTube】 How to Save Mobile Data Usage

莊郁如 · Accepted Answer

◆ Enable “Data Saver” mode
Tap your profile picture in the YouTube app → Go to Settings → Video quality preferences → Under Mobile networks, select Data saver.

◆ Adjust “Video Quality Preferences”
Open the YouTube app → Tap your profile picture → Settings → Video quality preferences → For Mobile networks, choose Data saver (e.g., 480p or lower).

◆ Turn off “Autoplay next video”
Tap your profile picture → Settings → Playback → Toggle off Autoplay next video.
This prevents continuous playback in case you fall asleep or forget to stop the video.

◆ Limit video preloading while browsing your feed
Tap your profile picture → Settings → Playback → Set Play videos in feeds to Off or Wi-Fi only.

◆ Turn off mobile data usage for the YouTube app
For iPhone:
Go to Settings → Mobile Data → Find YouTube → Toggle off to disable mobile data usage.

For Android:
Go to Settings → Apps → YouTube → Mobile data & Wi-Fi → Turn off Allow background data usage.

Question 28

【Facebook】 How to Save Mobile Data Usage

莊郁如 · Accepted Answer

◆Stop videos from auto-playing in your Facebook news feed
https://www.facebook.com/help/1406493312950827/?helpref=uf_share

◆Adjust the number of photos you want to see to control the data usage and loading speed on Facebook.
https://www.facebook.com/help/mobile-basic/656932384361200/

＜Quoted from Facebook＞

Question 29

How to Reduce Mobile Data Usage (Instagram / Threads)

莊郁如 · Accepted Answer

① Enable “Data Saver Mode”

Instagram App → Profile →【Settings and privacy】→【Data usage and media quality】

📌 Turn on “Use Less Mobile Data”
📌 This reduces video preloading and the loading of high-quality photos/videos.

② Limit Media Quality and Preloading

Instagram App →【Settings and privacy】→【Media quality】

📌 Recommended settings:

✔ High-quality media → Set to “Wi-Fi only” or turn off
✔ Video preloading → Limit or turn off (if available on your device)

📌 Prevents large amounts of video content from loading automatically while scrolling.

③ Turn Off Background Mobile Data (iPhone)

【Settings】→【Cellular】→【Instagram】

📌 Turn off mobile data access or limit background activity.
📌 Prevents the app from continuously using data in the background.

④ Threads (Same Account System)

Threads uses the same Meta system settings as Instagram.

📌 Recommended settings:

✔ Enable “Use Less Mobile Data”
✔ Limit high-quality media
✔ Turn off background data usage

Question 30

Are the product prices only available in Japanese yen (JPY)?

meng · Accepted Answer

Since we are a Japan-based telecommunications company, all product prices are displayed and charged in Japanese yen (JPY).

If you use a credit card or debit card issued outside Japan, some card issuers may charge a foreign transaction fee. Whether a fee applies and the amount charged depend on your card issuer’s policies. Please contact your card issuer directly for further details.

Question 31

Can I pay with a debit card?

meng · Accepted Answer

You can pay with credit cards or debit cards.

If you use a credit card or debit card issued outside Japan, some card issuers may charge a foreign transaction fee. The availability and amount of any additional fees depend on your card issuer’s policies. Please contact your card issuer directly for details.

Question 32

Can I change the details of my order?

meng · Accepted Answer

We are sorry, but we are unable to directly modify the order details.

If you need to make changes to your order information, please contact us through our official LINE account. We will assist you in confirming and processing the requested changes.

Question 33

Can I cancel my order and receive a refund?

meng · Accepted Answer

📌 JB eSIM / JB SIM Card
If we have not yet sent the eSIM activation URL or the physical SIM card has not yet been shipped, you may request order cancellation and a refund.

To cancel your order, please contact our customer support through our official LINE account (@913athnc) and provide the following information:

• Order number
• Customer name
• Customer email address

If you are unable to use LINE, you can also contact us via Email (info@jbrg.jp).

📢 Refund Information
• For cancellations due to customer reasons, a 5% credit card transaction fee will be deducted from the refund amount.
• For cancellations due to reasons caused by our company, a full refund will be issued.

📌 JB Voice SIM / JB Voice eSIM
Since the application process for a Japanese phone number begins immediately after the order is completed, cancellations and refunds are generally not available.

If you have special circumstances, please contact us through our official LINE account. We will review your case and assist you accordingly.

Question 34

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

meng · Accepted Answer

📌 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.

Question 35

Free Wi-Fi Services at Japanese Airports

meng · Accepted Answer

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.

Question 36

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

meng · Accepted Answer

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.

Question 37

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

meng · Accepted Answer

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.

Question 38

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

meng · Accepted Answer

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.

Question 39

Data eSIM Activation Guide

莊郁如 · Accepted Answer

Q1：Do I need to issue the QR Code immediately after receiving the Activation URL?

A: ❌ No, you do not need to issue it immediately.
🕒 Newly applied eSIMs have a 45-day QR Code issuance period.

Recommendation:
✅ Issue the QR Code before departure.
✅ This prevents the usage period from starting early due to flight changes, typhoons, or trip cancellations.

Q2：What does “Complete operation within 44 days, automatically activated on the 45th day” mean?

A:
This means:

📌 The Activation URL operation period before pressing “Issue”.
⏰ Please complete QR Code issuance within 45 days after receiving the Activation URL.
⚠️ If the QR Code is not issued after 45 days:
➡️ The system will automatically start counting the usage period.
➡️ The countdown will begin even if you are outside Japan.

Q3：Will the usage period start immediately after pressing “Issue”?

A: ❌ No.
Pressing “Issue” only generates the QR Code.
The usage period does not start immediately after issuance.
The following steps must be completed:
1️⃣ QR Code issuance
2️⃣ eSIM installation
3️⃣ Arrival in Japan
4️⃣ Smartphone connects to the docomo network
➡️ The eSIM will then be officially activated and the usage period will begin.

Q4：How is the usage period calculated?

A:
After eSIM activation:
🇯🇵 The usage period is calculated based on Japan Standard Time (JST) calendar days.
Example:
📅 7/14: Issue and install eSIM in Taiwan
📅 7/15: Arrive in Japan and connect to the docomo network, will be counted as Day 1.

Q5：Can I issue the QR Code during system maintenance?

A: System maintenance time: Every Tuesday 22:00～Every Wednesday 09:00 is the system maintenance period.
✅ Please complete QR Code issuance before Tuesday 22:00.
⚠️ If you operate during maintenance:
・The status may remain pending.
・The QR Code will be issued after maintenance is completed.

Q6：Do I need to keep the page open after pressing “Issue”?

A: ❌ No.
After pressing “Issue”:
✅ You may close the page.
✅ Open the Activation URL again later to check the result.
📌 You can check:
・QR Code issuance status
・Activation start/end dates
・Remaining data / used data capacity

Question 40

Can I receive Taiwan calls and SMS for free while in Japan?

meng · Accepted Answer

Yes, you can use this service if the following conditions are met:

✅ Your smartphone is connected to Wi-Fi
✅ The Wi-Fi Calling function is enabled
✅ You are using a supported device (iPhone / Android)
✅ Your SIM card remains active (not suspended or cancelled)

💰 Charges (Important)
Wi-Fi Calling is treated as if you are using the service in Taiwan.

📞 Making calls
・Calling a Taiwan number → Taiwan domestic call charges
・Calling a Taiwan mobile number → Taiwan domestic rates
・Calling overseas (e.g., Japan) → International call charges

👉 No international roaming charges will apply

📲 Receiving calls
・Receiving calls from Taiwan → Free (same as receiving calls in Taiwan)

🌟 Benefits
・Good call quality when the Wi-Fi connection is stable
・You can make and receive calls without enabling international roaming

Question 41

Can I use multiple SIM cards or eSIMs at the same time?

meng · Accepted Answer

🅰️ Yes, multiple SIM usage is supported.

If your smartphone supports Dual SIM or multiple SIM functionality, you can use multiple physical SIM cards and/or eSIMs at the same time for more flexible usage.

⚠️ The number of SIM cards/eSIMs that can be used depends on your device model and specifications. Please check your device compatibility before use.

Question 42

Use Your Taiwan Wi-Fi Calling Service in Japan

meng · Accepted Answer

Taiwan's major mobile carriers provide Wi-Fi Calling services.

➡ While you are in Japan, Wi-Fi Calling is treated as if you were using your phone in Taiwan.

📲 Receiving calls and SMS: Free

📲 Making calls and sending SMS: Charged at your Taiwan domestic rates

📶 Requirements

・Your phone is connected to Wi-Fi.

・Wi-Fi Calling is enabled on your phone (please refer to the attached guide).

・Your Taiwan SIM card is active.
(No international roaming subscription is required, so you don't need to worry about additional roaming charges.)

📞 How to Make Calls

Calling a Taiwan number

➡ Dial the Taiwan phone number directly without adding the country code.

Calling a Japan number

➡ Make an international call.
(Example: 009-81-...)

🌟 Benefits

・No need to enable international roaming.

・You can make and receive calls over Wi-Fi even in areas with poor mobile signal, such as indoors.

・The person you're calling will not know that you're overseas.

・You can also receive SMS verification codes while abroad.

Question 43

Yamato Transport Delivery Time Slots

meng · Accepted Answer

⏰ You may choose your preferred delivery time slot.

・Morning (8:00 AM – 12:00 PM)
・2:00 PM – 4:00 PM
・4:00 PM – 6:00 PM
・6:00 PM – 8:00 PM
・7:00 PM – 9:00 PM
・No Preferred Time Slot

Question 44

Any SIM restrictions？

莊郁如 · Accepted Answer

【 iOS Device】

「settings」➔「General」➔「About」➔「Carrier Lock」 ➔No SIM restrictions

【 Android Device】

You cannot determine this directly from the mobile phone. Please check with the place of purchase or the carrier you have a contract with.
SIM lock regulations vary by country. In Taiwan, most phones are not SIM-locked.Devices purchased in countries like Japan or the United States are more likely to have SIM lock issues.
📢If you have used SIM cards from different countries or carriers, the device is likely not SIM-locked.

Question 45

How many GB are needed about 1 day？

莊郁如 · Accepted Answer

Question 46

How long can 1GB last for internet usage？

莊郁如 · Accepted Answer

Question 47

How can I check the data usage of the voice SIM?

莊郁如 · Accepted Answer

🅰️ 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.

Question 48

Is the speed of a physical SIM card faster than an eSIM?

莊郁如 · Accepted Answer

The signal strength is mainly affected by the telecommunications company’s network infrastructure. The factors that influence the signal strength are as follows:

The distance to the base station
Presence of obstacles
Presence of signal interference
Antenna performance
Frequency band Since our company’s eSIM and SIM cards are products from Japan’s local docomo telecom company, using the same signal, the speed of our eSIM and SIM cards are the same. As for other international roaming eSIMs, there may be cases where roaming is done through smaller telecom companies, leading to significant differences in speed and coverage.

Question 49

docomo’s System Maintenance Time

莊郁如 · Accepted Answer

Regular maintenance hours (Japan Time)

Every Tuesday from 10:00 PM to Wednesday 9:00 AM

■eSIM
During the system maintenance period, issuing eSIM activation QR codes will not be possible.
If the “Issue” button has already been pressed, the status will remain as “Pending.”
You may exit the screen and return later via the link to check the issuance result.
If the activation code has already been issued, you can still proceed with “Add eSIM” and begin using the service, even during maintenance.

■SIM Card
Inserting a physical SIM card into a smartphone or other device during the maintenance period may result in no response.
However, there is no need to worry — the system will automatically complete the activation process in order once maintenance is finished.
SIM cards that are already in use will not be affected.

■Voice SIM Card
Voice SIM cards are pre-activated before delivery and are therefore not affected by system maintenance.

Temporary Maintenance hours (Japan Time)

① Sep. 24, 2025, 10:00 PM ～ Sep. 25, 2025, 9:00 AM

■Functions Temporarily Unavailable

New line activation for physical SIMs will not be available
Activation codes for eSIMs will not be issued

■Notes

Physical SIMs that request activation during the maintenance will be activated sequentially after the maintenance ends.
Activation codes requested during the maintenance will be issued sequentially after the maintenance ends.
SIM cards that have already been activated and are in use will not be affected.
Activation codes that have already been issued can still be installed and used during the maintenance period.

Question 50

Why is it better to choose docomo products for prepaid cards?

莊郁如 · Accepted Answer

🅰️The prepaid card uses a 4G/LTE mobile network, and docomo has the most base stations in Japan, offering the widest coverage. Please refer to the comparison table below.
When you go to areas outside major cities in Japan, you will notice a significant difference.

Question 51

Why is the signal bar not showing on my iPhone?

莊郁如 · Accepted Answer

🅰️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

Question 52

How can I check if the area I want to use has signal?

莊郁如 · Accepted Answer

🅰️Our company uses the services of Japan’s largest mobile communications company, docomo, which has the widest coverage.
You can use the following website to enter an address and check the 4G/LTE service coverage:
👉docomo Mobile Network Service Area Search

Question 53

Once the purchased high-speed data is used up, will I no longer be able to access the internet?

莊郁如 · Accepted Answer

🅰️You will not be disconnected within the validity period and can use the internet with a speed of 200kbps indefinitely.
High-speed data can be added as needed. 👉【eSIM/SIM】Recharge

Question 54

Is it possible to extend the validity period of the eSIM or add more data?

莊郁如 · Accepted Answer

🅰️All eSIMs can have their validity period extended or additional high-speed data added.

You can top up or extend within the validity period.
Remaining data and newly added data are treated the same; there is no usage priority between the two.
There is no limit to the number of top-ups or extensions.
If you top up within 7 days after the expiration date, the data balance will be reset to zero, but you can continue using the original eSIM or SIM card.
The extension period is calculated from the 2nd day after the original expiration date, which is considered the first day of the new validity period.
After purchase, in addition to receiving an email with an electronic receipt, you will also receive a separate activation notice from our company via biz@jbrg.jp.
You may request a cancellation before receiving the activation notice. However, a 5% processing fee will be deducted to cover credit card company fees.
If you apply for an extension after 6:00 PM on the last day of validity, please contact customer service for confirmation before making the purchase to avoid delays in processing.
After the initial validity period ends, the online inquiry system [eSIM Activation URL] will no longer reflect the extended validity or remaining data. Please use your mobile device’s data usage statistics instead.
All JBeSIM plans are eligible for top-up and extension. JB SIM cards with data capacity (X-GB) can be topped up, while time-based plans (6/8/16/31 unlimited) cannot be extended.

Question 55

What sizes are there for SIM cards?

莊郁如 · Accepted Answer

🅰️ 3-in-1 SIM cards (nano, micro, standard).
There are notches around the IC chip for nano, micro, and standard sizes. Use your finger to push out the required size from the back.
Be sure to handle the IC chip carefully when removing it to avoid damaging it.

Question 56

How long will it take to receive the SIM card after purchase?

莊郁如 · Accepted Answer

🅰️In principle, the item will be shipped on the same day or the next day after purchase.

For the Taiwan region, it will be shipped via registered mail through the post office. Please refer to the official website of the post office. *The shipping method will be based on the buyer’s scheduled start date of use. If it’s too close to the date, we may switch to time-limited registered mail.

For the Japan region, it will be shipped via Takkyubin (courier service). Please refer to the official website of Black Cat Takkyubin.

Question 57

Is it possible to extend the validity period of the SIM card or add more data capacity?

莊郁如 · Accepted Answer

🅰️📢The 6/8/16/31days unlimited SIM cards cannot be extended or topped up. The fixed data SIM cards can have their validity period extended or additional high-speed data added. Please refer to the 🛒SIM_recharge/extension

※Make sure to purchase the extension or top-up products online within the validity period.

※If it is within 7 days after the validity period has expired, top-ups are possible, but the remaining data will be reset to 0.

※Please use your phone or tablet’s statistics feature to check your data usage. Refer to “How to check your mobile data usage”

You can top up or extend within the validity period.
Remaining data and newly added data are treated the same; there is no usage priority between the two.
There is no limit to the number of top-ups or extensions.
If you top up within 7 days after the expiration date, the data balance will be reset to zero, but you can continue using the original eSIM or SIM card.
The extension period is calculated from the 2nd day after the original expiration date, which is considered the first day of the new validity period.
After purchase, in addition to receiving an email with an electronic receipt, you will also receive a separate activation notice from our company via biz@jbrg.jp.
You may request a cancellation before receiving the activation notice. However, a 5% processing fee will be deducted to cover credit card company fees.
If you apply for an extension after 6:00 PM on the last day of validity, please contact customer service for confirmation before making the purchase to avoid delays in processing.
After the initial validity period ends, the online inquiry system [eSIM Activation URL] will no longer reflect the extended validity or remaining data. Please use your mobile device’s data usage statistics instead.
All JBeSIM plans are eligible for top-up and extension. JB SIM cards with data capacity (X-GB) can be topped up, while time-based plans (6/8/16/31 unlimited) cannot be extended.

Question 58

How can I check the data usage of my SIM Card？

莊郁如 · Accepted Answer

🅰️Since physical SIM cards do not provide online real-time data usage checking services, you need to use the statistics feature on your phone or tablet. Please refer to the “How to check your mobile data usage“

Question 59

Can I insert the SIM card into my phone outside of Japan first?

莊郁如 · Accepted Answer

🅰️ Yes, it’s fine.
Since our company’s SIM card is a product from a Japanese telecom provider and not an international roaming type, it will not be activated when inserted into the phone outside of Japan, as it won’t be able to receive the docomo signal from Japan.
To avoid forgetting the SIM ejector tool when traveling abroad or accidentally losing the SIM card while out, we recommend inserting the SIM card into the phone ahead of time.
For dual-SIM phones, typically the SIM card you’re using is inserted in the SIM1 slot, so you can insert the Japanese SIM card into the SIM2 slot as a backup.
※The SIM card will display “No Service/Unknown Number”.

Question 60

Can I Use Personal Hotspot for Free?

莊郁如 · Accepted Answer

🅰️ Yes! No additional application or activation is required. 😊

All JB SIM and JB eSIM products support Personal Hotspot at no extra charge.

⚠️ Before using Personal Hotspot, you must configure the Personal Hotspot APN settings. Otherwise, you won't be able to share your mobile data connection with other devices.

Question 61

How to Configure APN for Personal Hotspot

莊郁如 · Accepted Answer

🅰️ To share your mobile data connection with a computer, tablet, or other devices using Personal Hotspot, you must first configure the APN settings.

🍎 iPhone (iOS)

📱 Single SIM

Settings ➡ Cellular ➡ Cellular Data Network

Enter the following information under both Cellular Data and Personal Hotspot:

✔ APN
✔ Username
✔ Password

📱 Dual SIM / Multiple SIMs

Settings ➡ Cellular ➡ Select the SIM you want to configure ➡ Cellular Data Network

Enter the following information under both Cellular Data and Personal Hotspot:

✔ APN
✔ Username
✔ Password

⚠️ Each SIM has its own APN settings. Be sure to select the correct SIM before making any changes.

⚠️ In most cases, you should configure the SIM currently selected for Cellular Data.

✅ After the APN is configured

A Personal Hotspot option will appear in Settings.

Turn on:

✔ Allow Others to Join

We also recommend changing your Wi-Fi password before sharing your connection.

📌 To check your Wi-Fi (device) name:

Settings ➡ General ➡ About ➡ Name

🤖 Android

For Android devices, whether you are using an eSIM or a physical SIM card, you must configure the APN before you can access mobile data or use the Personal Hotspot feature.

Using Samsung as an example:

Settings ➡ Connections ➡ Mobile Networks ➡ Access Point Names (APN) ➡ Tap ＋ (Add)

Enter the APN information provided with your SIM:

✔ APN
✔ Username
✔ Password

Save the settings when finished. You can then use mobile data and the Personal Hotspot feature.

⚠️ The menu layout may vary depending on the Android brand and model, but the setup process is generally the same.

Question 62

How do I turn on Personal Hotspot or change the password?

莊郁如 · Accepted Answer

🍎 iPhone (iOS)

📌 Turn on Personal Hotspot:
【Settings】 ➡ 【Personal Hotspot】 ➡ Turn on 【Allow Others to Join】
You can then share your mobile data connection with other devices.

📌 Change Wi-Fi Password:
【Settings】 ➡ 【Personal Hotspot】 ➡ 【Wi-Fi Password】
Enter a new password and save the settings.

📌 View or Change Wi-Fi Name:
【Settings】 ➡ 【General】 ➡ 【About】 ➡ 【Name】

This device name will be displayed as the Wi-Fi hotspot name when other devices search for available networks.

🤖 Android

※ The operation interface may vary depending on the brand and model. The following example uses Samsung A55.

📌 Turn on Personal Hotspot:
【Settings】 ➡ 【Connections】 ➡ 【Mobile Hotspot and Tethering】 ➡ Turn on 【Mobile Hotspot】

You can then share your mobile data connection with other devices.

📌 Change Wi-Fi Name or Password:
【Settings】 ➡ 【Connections】 ➡ 【Mobile Hotspot and Tethering】 ➡ 【Mobile Hotspot】

📌 Tap 【Network Name】 or 【Password】
to enter the settings page and modify the hotspot name and password.

Question 63

I have completed the settings according to the instructions, but why can I still not use the Personal Hotspot function?

莊郁如 · Accepted Answer

🅰️ Please check the following items first:

① Confirm that the APN is set for the correct SIM/eSIM

If your phone uses multiple SIM cards or eSIMs at the same time, the most common issue is that the APN was set for the wrong SIM card.

Please confirm that the SIM/eSIM currently used for Mobile Data is the same SIM/eSIM where the APN settings were entered.

② Restart your device after completing the settings

After completing the APN settings, please restart your phone once and test the Personal Hotspot function again.

③ Recheck the APN information

Please carefully verify the following information:

✔ APN
✔ Username
✔ Password

Make sure all settings exactly match the information provided in the instruction manual.

⚠️ Important Notes

Due to the wide variety of smartphone brands, models, and operating system versions, the settings screens may differ depending on the device. Therefore, we cannot guarantee that the Personal Hotspot function will work on every device.

However, as of now, we have not received any cases where the Personal Hotspot function could not be used due to an issue with the JB SIM/eSIM itself.

Question 64

Can I set up the Personal Hotspot APN before arriving in Japan?

莊郁如 · Accepted Answer

🅰️ Yes, you can.
We recommend completing the APN settings before departure, so you can use the Personal Hotspot function immediately after arriving in Japan.

⚠️ However, our SIM/eSIM products use Japanese local mobile networks and are not international roaming products. Therefore, they cannot connect to the Japanese Docomo network while you are outside Japan. Even if the APN settings have been completed, you will not be able to confirm whether the settings are successful or test the Personal Hotspot function overseas.

📌 In short:
✔ You can set up the APN before traveling.
✔ You can use it after arriving in Japan.
❌ You cannot test whether the APN settings are working while outside Japan.

This is a normal situation. Please test the connection after arriving in Japan and connecting to the mobile network.

FAQ

JB Data eSIM

Important Notes Before Purchase

Any SIM restrictions？

【 iOS Device】

【 Android Device】

How many GB are needed about 1 day？

How long can 1GB last for internet usage？

Is the speed of a physical SIM card faster than an eSIM?

How can I check if the area I want to use has signal?

【iPhone】 How to Save Mobile Data Usage

【YouTube】 How to Save Mobile Data Usage

【Facebook】 How to Save Mobile Data Usage

How to Reduce Mobile Data Usage (Instagram / Threads)

① Enable “Data Saver Mode”

② Limit Media Quality and Preloading

③ Turn Off Background Mobile Data (iPhone)

④ Threads (Same Account System)

Products

Why is it better to choose docomo products for prepaid cards?

How can I check the data usage and validity period of my eSIM?

Once the purchased high-speed data is used up, will I no longer be able to access the internet?

Is it possible to extend the validity period of the eSIM or add more data?

Online Shopping

Are the product prices only available in Japanese yen (JPY)?

Can I pay with a debit card?

Can I change the details of my order?

Can I cancel my order and receive a refund?

Activation & Usage

When does the validity period start counting?

Can I receive Taiwan calls and SMS for free while in Japan?

💰 Charges (Important)Wi-Fi Calling is treated as if you are using the service in Taiwan.

🌟 Benefits・Good call quality when the Wi-Fi connection is stable・You can make and receive calls without enabling international roaming

Use Your Taiwan Wi-Fi Calling Service in Japan

📶 Requirements

📞 How to Make Calls

🌟 Benefits

docomo’s System Maintenance Time

Why is the signal bar not showing on my iPhone?

Can the QR for activating eSIM be issued in advance overseas?

Can I add eSIM while outside Japan?

Why can’t the eSIM be fully activated while outside of Japan?

What should I do if I cannot scan the QR code on my own phone after issuing it from my phone?

Why can’t my iPhone scan QR codes?

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

Free Wi-Fi Services at Japanese Airports

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

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

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

Data eSIM Activation Guide

Personal Hotspot

Can I Use Personal Hotspot for Free?

How to Configure APN for Personal Hotspot

🍎 iPhone (iOS)

📱 Single SIM

📱 Dual SIM / Multiple SIMs

✅ After the APN is configured

🤖 Android

How do I turn on Personal Hotspot or change the password?

🍎 iPhone (iOS)

🤖 Android

I have completed the settings according to the instructions, but why can I still not use the Personal Hotspot function?

① Confirm that the APN is set for the correct SIM/eSIM

② Restart your device after completing the settings

③ Recheck the APN information

Can I set up the Personal Hotspot APN before arriving in Japan?

When using multiple SIM cards or eSIMs at the same time, do I need to set a separate Personal Hotspot name or password for each one?

JB Data SIM

Important Notes Before Purchase

Any SIM restrictions？

【 iOS Device】

【 Android Device】

How many GB are needed about 1 day？

How long can 1GB last for internet usage？

Is the speed of a physical SIM card faster than an eSIM?

How can I check if the area I want to use has signal?

【iPhone】 How to Save Mobile Data Usage

【YouTube】 How to Save Mobile Data Usage

【Facebook】 How to Save Mobile Data Usage

How to Reduce Mobile Data Usage (Instagram / Threads)

💰 Charges (Important)
Wi-Fi Calling is treated as if you are using the service in Taiwan.

🌟 Benefits
・Good call quality when the Wi-Fi connection is stable
・You can make and receive calls without enabling international roaming

💰 Charges (Important)
Wi-Fi Calling is treated as if you are using the service in Taiwan.

🌟 Benefits
・Good call quality when the Wi-Fi connection is stable
・You can make and receive calls without enabling international roaming