When choosing an eSIM for traveling to Japan, many people may wonder, "Does it come with a Japanese phone number?" "Can I receive SMS authentication?" "Can I make calls using LINE or WhatsApp?"
There are two main types of Japanese eSIMs: data-only eSIM and eSIM with a phone number.
With a data-only eSIM, you can use internet communication, but it does not support voice calls or SMS sent and received via regular phone lines. On the other hand, an eSIM with a phone number allows you to use voice calls and SMS depending on the plan.
In this article, we will clearly explain whether you can use a phone number and SMS with a Japanese eSIM, the differences from a data-only eSIM, and how to differentiate between your main line during your trip.
Can you use a phone number and SMS with a Japanese eSIM?
Whether you can use a phone number and SMS with a Japanese eSIM depends on the eSIM plan you purchase.
Generally, there are two types:
- Data-only eSIM: Internet communication only
- eSIM with a phone number: In addition to data communication, voice calls and SMS are available
Most Japanese eSIMs sold for travel are data-only. If the product page does not mention support for phone numbers, voice calls, or SMS, it is likely that regular phone calls and SMS cannot be used.
Before purchasing, please check the Japanese eSIM product and pricing plans to confirm the supported communication features.
What is a data-only eSIM?
A data-only eSIM is an eSIM that can only be used for mobile data communication.
You can use the following internet services that are necessary during your trip to Japan:
- Google Maps and map apps
- Transit navigation
- Browsing websites
- SNS
- Translation apps
- Calling and messaging apps like LINE and WhatsApp
- Watching videos
However, data-only eSIMs typically do not come with a Japanese phone number for voice calls. Therefore, you cannot make calls using the standard phone app on your smartphone or send and receive SMS to mobile phone numbers.
You can use calling apps like LINE
Even with a data-only eSIM, you can use calling apps like LINE, WhatsApp, Messenger, FaceTime, and Skype that utilize internet communication.
As long as both parties are using the same app, you can make voice and video calls without needing an eSIM with a phone number.
However, video calls consume a lot of data. If you want to check the necessary data capacity during your trip, please refer to data usage estimates.
What is an eSIM with a phone number?
An eSIM with a phone number is an eSIM that allows you to use a phone number in addition to data communication.
Depending on the plan, you can use the following features:
- Making voice calls
- Receiving voice calls
- Sending SMS
- Receiving SMS
- Receiving SMS authentication codes
- Mobile data communication
However, even if it comes with a phone number, not all plans support making and receiving calls or sending and receiving SMS.
For example, some plans may only support receiving SMS, only allow incoming voice calls, or have limits on call duration, so the conditions vary by product.
If you need a phone number, please check the plans for eSIMs with a phone number to confirm the available features and conditions.
Differences between data-only eSIM and eSIM with a phone number
| Feature | Data-only eSIM | eSIM with a phone number |
|---|---|---|
| Mobile data communication | Available | Available |
| Japanese phone number | Generally none | Yes |
| Calls using the standard phone app | Not available | Available depending on the plan |
| SMS sending and receiving | Not available | Available depending on the plan |
| LINE/WhatsApp calls | Available | Available |
| SMS authentication | Not available with Japanese eSIM | Available if SMS receiving is supported |
| Cost | Tends to be relatively cheap | Tends to be relatively expensive |
If your main use is for maps, SNS, translation, and messaging apps, a data-only eSIM may be sufficient.
If you need to make calls to stores or hotels in Japan, receive SMS authentication, or use services that require a Japanese phone number, an eSIM with a phone number is convenient.
Can you make regular calls with a data-only eSIM?
With a data-only eSIM, you cannot make calls to mobile or landline numbers using the standard phone app on your smartphone.
However, you can use calling apps that utilize internet connections.
Calling methods available with a data-only eSIM
- LINE calls
- WhatsApp calls
- Facebook Messenger calls
- FaceTime audio
- Google Meet
- Zoom
- Other VoIP apps
If the other party is using the same app, you can contact them without any issues using a data-only eSIM.
On the other hand, if you need to contact general phone numbers for hotels, restaurants, hospitals, or transportation, it is advisable to prepare an eSIM with a phone number or another means of communication.
Can you receive SMS with a data-only eSIM?
A data-only eSIM itself cannot send or receive regular SMS. This is because it does not have a Japanese mobile phone number assigned to it, so it cannot be used as a destination for SMS.
However, if you keep your main line active on your smartphone, you may be able to receive SMS sent to that main line's phone number.
If you are receiving SMS on your main line, please pay attention to the following points:
- Do not turn off the main line
- Turn off data roaming on the main line
- Select the Japanese eSIM for data communication
- Check with your carrier about SMS receiving charges while abroad
- Also check the charges for incoming voice calls
Whether SMS receiving is free or charged depends on the carrier and the pricing plan you have. Please check the overseas usage conditions with your carrier before your trip.
Can you receive SMS authentication codes?
For online services, credit card payments, and banking apps, you may need an SMS authentication code.
With a data-only Japanese eSIM, you cannot receive SMS authentication codes sent to the Japanese eSIM.
The main options for using SMS authentication are as follows:
- Keep your regular line ON
- Use an eSIM with a phone number that supports SMS receiving
- Change to an authentication app or email verification in advance
- Log in to necessary services before your trip
Be cautious of SMS authentication that requires a Japanese phone number
Some services in Japan may require SMS authentication using a Japanese mobile phone number.
Even with an eSIM with a phone number, it does not guarantee that it can be used for identity verification for that service. Numbers issued for data communication, short-term use, or those issued overseas may not be eligible for verification.
If you are purchasing an eSIM with a phone number for the purpose of registering for a specific service, please check the service's usage conditions in advance.
How to use Japanese eSIM and main line together
With a dual SIM compatible smartphone, you can use the Japanese eSIM for data communication while maintaining your regular main line for phone numbers and SMS.
The general settings are as follows:
- Mobile data communication: Japanese eSIM
- Data roaming for Japanese eSIM: ON
- Data roaming for main line: OFF
- Default voice line for calls: main line or select each time
- Automatic switching of mobile data communication: OFF
With this setting, you can use the Japanese eSIM for internet communication while receiving incoming calls and SMS to your main line's phone number.
However, please note that international roaming charges may apply for incoming and outgoing calls while abroad. Some contracts may incur charges just for receiving a call.
For detailed methods on adding eSIMs or switching lines, please refer to how to set up eSIM.
How to differentiate between phone number and data line on iPhone
When using a Japanese eSIM and main line together on an iPhone, check the following settings:
- Open "Settings"
- Select "Cellular"
- Select the Japanese eSIM for "Cellular Data"
- Turn OFF "Allow Cellular Data Switching"
- Turn ON data roaming for the Japanese eSIM
- Turn OFF data roaming for the main line
- Select the phone line to use for "Default Voice Line"
If you keep the main line ON, you may be able to receive calls and SMS on your regular phone number depending on your contract.
However, to prevent overseas communication charges, please ensure that data roaming for the main line is turned OFF.
How to differentiate between phone number and data line on Android
On Android, the names of the settings screens may vary by manufacturer and model. Generally, you can set it up with the following steps:
- Open "Settings"
- Select "Network & Internet" or "Connections"
- Select "SIM" or "SIM Manager"
- Select the Japanese eSIM for mobile data
- Set the SIM to use for calls and SMS to the main line or confirm each time
- Turn ON data roaming for the Japanese eSIM
- Turn OFF data roaming for the main line
The names of the settings may differ depending on the device manufacturer, such as Samsung Galaxy, Google Pixel, or Xiaomi.
To check if your intended smartphone supports dual SIM or eSIM, please refer to the list of eSIM compatible devices.
Who should consider an eSIM with a phone number?
An eSIM with a phone number is suitable for the following individuals:
- Those who want to call hotels or stores in Japan
- Those who need a Japanese phone number for work
- Those who want to send and receive SMS
- Those who want to provide a phone number as a contact in Japan
- Those who want to call someone who does not use calling apps
- Those who want to increase their means of communication in case of emergencies
However, please note that eSIMs with a phone number may be more expensive than data-only eSIMs. Compare call time, SMS count, and available duration before making a choice.
Who should consider a data-only Japanese eSIM?
A data-only Japanese eSIM is suitable for the following individuals:
- Those who primarily use maps and transit navigation
- Those who communicate via LINE or WhatsApp
- Those who prioritize data communication for videos and SNS
- Those who can receive SMS on their regular main line
- Those who want to keep costs down
- Those who do not need a Japanese phone number
If your main use is data communication, a data-only eSIM is a simple and easy-to-use option.
For choosing based on travel days and usage purposes, please also refer to comparison of Japanese eSIM pricing and plans.
Points to note when using phone calls and SMS with a Japanese eSIM
Different functions even with a phone number
eSIMs with a phone number come in various types, such as those that support voice calls, those that only support SMS, and those that only support incoming calls.
Just because it has a phone number does not mean you can use all calling and SMS functions.
Additional call charges may apply
Even with an eSIM with a phone number, call charges may not be included in the plan price. Additional charges may apply depending on the destination and call duration.
International calls may not be supported
While some plans may support calls to Japanese phone numbers, they may not support international calls to overseas destinations.
There may be restrictions on SMS sending
While SMS receiving may be supported, there may be plans that do not allow SMS sending or have limits on the number of messages that can be sent.
Check the validity period of the phone number
Phone numbers for short-term travel eSIMs will become unusable after the plan's usage period ends. Be cautious if you plan to use it as a registration phone number for long-term services.
Check overseas charges for the main line
Even if you are using data communication with a Japanese eSIM, using calls or SMS on your main line may incur overseas roaming charges.
Check items if you cannot use phone calls or SMS
If you purchased an eSIM with a phone number but cannot use calls or SMS, please check the following items:
- Does the purchased plan support voice calls and SMS?
- Is the eSIM line ON?
- Is the line selected correctly for calls and SMS?
- Has the usage start date passed?
- Is there remaining balance for calls or SMS usage?
- Is the destination phone number entered correctly?
- Is it a destination that requires a country code?
- Is airplane mode OFF?
If you cannot use data communication either, please check the settings for APN, data roaming, and mobile data line.
For detailed troubleshooting methods, please refer to troubleshooting when the eSIM is not connecting. If the issue persists, please check eSIM setup and support information before deleting the eSIM.
Frequently Asked Questions about Japanese eSIM phone numbers and SMS
Does a data-only eSIM have a phone number?
Data-only eSIMs typically do not come with a phone number that can be used for voice calls or SMS. Even if information resembling a number appears in the device's settings, it does not guarantee that it can be used as a call number.
Can I use LINE with a data-only eSIM?
Yes. LINE uses internet communication, so you can use messaging, voice calls, and video calls with a data-only eSIM.
Can I receive SMS authentication with my regular phone number?
If you keep your main line active on your smartphone, you may be able to receive SMS even while abroad. However, please check the overseas usage conditions and charges with your carrier.
Can I register for Japanese services with an eSIM with a phone number?
It is not guaranteed that you can register. Some services may only accept verified mobile phone numbers or long-term contract numbers.
Can I make emergency calls with a data-only eSIM?
You cannot use regular voice call functions with a data-only eSIM. Be sure to check alternative means of communication, such as your main line, an eSIM with a phone number, the phone at your accommodation, or asking people around you in case of emergencies.
Can I use LINE with an eSIM with a phone number?
Yes. If the plan supports mobile data communication, you can also use internet services like LINE.
For other questions, please refer to frequently asked questions about eSIM.
Conclusion | Check if you need calls or SMS and choose a Japanese eSIM
Japanese eSIMs come in data-only plans and plans with a phone number.
With a data-only eSIM, you can use maps, SNS, translation, and LINE calls, but it does not support regular voice calls or SMS.
If you need a Japanese phone number, calls using the standard phone app, or SMS authentication, consider an eSIM with a phone number.
When choosing a Japanese eSIM, please check the following points:
- Is it data-only or with a phone number?
- Does it support making and receiving voice calls?
- Does it support sending and receiving SMS?
- Are call and SMS charges included?
- What is the validity period of the phone number?
- If using in conjunction with the main line, what are the overseas charges?
If you want to summarize the selection, pricing, and setup methods for Japanese eSIMs, please refer to the complete guide to Japanese eSIM.
For those preparing a communication plan for traveling to Japan, you can check the plans that suit your needs from Japanese eSIM products and pricing plans.
