When using eSIM for travel to Japan, temporary return, business trips, or studying abroad, many may wonder, "If I have a phone number attached to my eSIM, can I make and receive regular calls?"
With a phone number attached to an eSIM, if you have a plan that supports voice calls, you can use the standard phone app on your smartphone to make regular calls.
However, just because it says "with phone number" does not guarantee that voice calls can be made.
Depending on the product, even if a phone number is displayed, it may be for data communication only, may only support SMS reception, or may allow incoming calls but have restrictions on outgoing calls.
Additionally, even if voice calls are supported, the conditions for call charges, international calls, emergency calls, toll-free numbers, and short numbers vary by plan.
In this article, we will clearly explain the conditions for making and receiving calls with a phone number attached to an eSIM, how to make calls, incoming call settings, call charges, and what to check if you cannot use it.
What is a phone number attached to eSIM?
A phone number attached to an eSIM is an eSIM that can be used for data communication in addition to having a phone number.
Depending on the plan, you may be able to use the following features:
- Mobile data communication
- Outgoing domestic calls
- Incoming domestic calls
- Outgoing international calls
- Incoming calls from abroad
- SMS reception
- SMS sending
- Receiving SMS authentication codes
However, not all of these features are guaranteed to be included.
"With phone number," "voice compatible," and "SMS compatible" may represent different functionalities.
For details on phone number attached plans, please check phone number attached eSIM.
Can I make and receive calls with a phone number attached to eSIM?
If you have a phone number attached to an eSIM that supports voice calls, you can make and receive regular calls.
You will use the phone app that is standard on your smartphone, just like you would with a regular SIM card.
However, the supported features may vary depending on the plan you purchase.
| Type of Plan | Phone Number | Outgoing Calls | Incoming Calls | SMS |
|---|---|---|---|---|
| Data-only eSIM | Generally none | Not supported | Not supported | Not supported |
| eSIM with number display only | May be displayed | May not be supported | May not be supported | Varies by product |
| SMS compatible eSIM | Available | Varies by product | Varies by product | Receive or send/receive |
| Voice call compatible eSIM | Available | Supported | Supported | Varies by product |
| Voice & SMS compatible eSIM | Available | Supported | Supported | May support sending/receiving |
Before purchasing, please check if it states "supports outgoing and incoming voice calls."
Just because a phone number is displayed does not mean you can make calls
Even if a phone number is displayed in the smartphone's settings, it does not guarantee that you can make calls with that number.
The telecommunications provider may have assigned the number for line management, and it may not be usable for voice calls or SMS.
Whether you can make calls or not is determined not by whether the number is displayed on the device, but by the features of the plan you purchased.
Check the following items on the product page:
- Voice call support
- Domestic outgoing call support
- Domestic incoming call support
- International call support
- Call duration
- Call charges
Check outgoing and incoming call support separately
With a phone number attached to an eSIM, the conditions for outgoing and incoming calls may differ.
For example, there are products where incoming calls are free, but outgoing calls require an additional fee, or products where only a certain amount of domestic calls are included in the plan fee.
| Check Item | What to Check |
|---|---|
| Domestic Outgoing Calls | Can you call mobile and landline numbers within Japan? |
| Domestic Incoming Calls | Can you receive calls from within Japan? |
| International Outgoing Calls | Can you call overseas numbers? |
| Incoming Calls from Abroad | Can you receive calls while outside Japan? |
| Call Charges | Is it pay-per-use or does it include free calls? |
| Excluded Numbers | Can you call emergency numbers or toll-free numbers? |
How to make calls with a phone number attached to eSIM
After setting up an eSIM that supports voice calls, you can make calls from the standard phone app on your smartphone.
When making calls to domestic numbers
- Open the phone app on your smartphone
- Enter the phone number
- Press the call button
- Select the line to use for the call
- Select the phone number attached eSIM
If you are using dual SIM with multiple lines, make sure you are calling from the phone number attached eSIM and not the primary overseas line.
When calling a registered contact
- Open the phone app or contacts app
- Select the contact
- Press the phone icon
- Select the phone number attached eSIM as the outgoing line
The line you used once may be remembered as the default line for future calls.
Check the display of the line before making a call.
How to select the outgoing line on iPhone
If you are using multiple SIMs on an iPhone, you can select the line to use before making a call.
- Open the "Phone" app
- Display the keypad
- Check the line name at the top of the screen
- Tap the line name
- Select the phone number attached eSIM
- Enter the phone number and make the call
You may also be able to set a default line for each contact.
If you accidentally make a call from the primary overseas line, you may incur international roaming call charges.
How to select the outgoing line on Android
On Android, you can also select the line to use when making calls on dual SIM compatible devices.
- Open the phone app
- Select the phone number or contact
- Check the displayed SIM selection button
- Select the phone number attached eSIM
- Make the call
Depending on the model, you may be able to specify "SIM for calls" or "preferred SIM" from the settings screen.
On Android, the names of the settings may vary depending on the manufacturer and OS version.
How to receive calls with a phone number attached to eSIM
If the phone number attached eSIM that supports incoming calls is active, you can generally receive calls just like a regular phone.
When a call comes in, the caller's phone number or registered name will be displayed on the smartphone's incoming call screen.
To receive calls, please check the following conditions:
- The line for the phone number attached eSIM is ON
- It is within the validity period of the eSIM
- Signal is displayed
- Airplane mode is OFF
- Call rejection settings are not enabled
- Check do not disturb mode or focus mode
- Connected to the telecommunications provider's network
Even if you have selected another eSIM for mobile data communication, you may still receive calls if the line for the phone number attached eSIM is active.
Can I receive calls while using dual SIM?
On dual SIM compatible devices, you can activate both the primary overseas line and the phone number attached eSIM simultaneously.
If both lines support waiting, you may be able to receive calls to both numbers.
However, some devices may not allow incoming calls to the other line while one line is in use.
The compatibility depends on the device's dual SIM functionality and communication method.
| Setting Item | Primary Overseas Line | Phone Number Attached eSIM |
|---|---|---|
| Line | ON as needed | ON |
| Mobile Data Communication | Not used | Used |
| Data Roaming | OFF | Follow product instructions |
| Standard Voice Line | Set as needed | Set for domestic calls in Japan |
| Automatic Data Switching | OFF is recommended | |
How to set the standard voice line
If you find it cumbersome to select the line every time you make a call, you can set the phone number attached eSIM as the standard voice line.
For iPhone
- Open "Settings"
- Select "Mobile Data"
- Select "Default Voice Line"
- Select the phone number attached eSIM
For Android
- Open "Settings"
- Select "Network & Internet" or "Connections"
- Select "SIM" or "SIM Manager"
- Select "Calls" or "Preferred SIM"
- Select the phone number attached eSIM
Depending on the device, you may be able to select "Ask every time."
If you want to switch between the primary overseas line and the phone number attached eSIM, the "Ask every time" setting is also convenient.
How to make calls within Japan
When making calls from a Japanese phone number attached eSIM to mobile or landline numbers within Japan, enter the phone number in the usual domestic format.
- Mobile phone: Numbers starting with 090, 080, 070, etc.
- Landline: Numbers starting with the area code
- IP phone: Numbers starting with 050
When using within Japan, you can generally call without adding "+81."
However, depending on the device or service, you may be able to automatically call even if the phone number is registered in international format.
How to make international calls to overseas phone numbers
If the phone number attached eSIM supports international calls, you will need to include the country code when making the call.
The general input method is as follows:
- Enter "+"
- Enter the country code of the recipient
- Remove the "0" at the beginning of the phone number
- Enter the remaining phone number
- Make the call
For example, when calling a "090" number in Japan from abroad, you would enter it in the format "+81 90."
The ability to make international calls and the call charges vary by plan.
With eSIMs that do not support international calls, you may not be able to call overseas numbers from the standard phone app.
Call charges for phone number attached eSIM
The call charges for phone number attached eSIMs mainly fall into the following types:
| Charge Type | Features |
|---|---|
| Pay-per-use | Charges apply based on call duration |
| Free calls included | Included in the plan fee up to a certain duration |
| Flat rate for domestic calls | Allows unlimited use of eligible domestic calls for a flat fee |
| Free incoming calls | Incoming calls are free, with charges only for outgoing calls |
| Chargeable | Calls are made by adding balance |
If you make long calls without checking the call charges, additional fees may become high.
Before purchasing, please check the following points:
- Charge per minute for domestic outgoing calls
- Incoming call charges
- International call charges
- Free call duration
- How to check call balance
- How to add balance
- Excluded phone numbers
Are there charges for incoming calls?
When using a Japanese phone number attached eSIM within Japan, many products offer free incoming calls.
However, depending on the type of plan, the country of use, and roaming conditions, there may be charges for incoming calls.
In particular, when using a Japanese phone number attached eSIM outside of Japan, it may be treated as international roaming.
Please check the incoming call charges for domestic and overseas use separately.
Can I also use SMS with a phone number attached eSIM?
Even if the phone number attached eSIM supports voice calls, it does not necessarily include SMS functionality.
Depending on the product, there may be differences such as:
- Only supports SMS reception
- Supports sending and receiving domestic SMS
- Also supports international SMS
- Not SMS compatible
- Does not support SMS from short numbers
If you plan to use SMS authentication, please check for SMS reception support.
However, even if you can receive SMS, it does not guarantee that you can authenticate via SMS for all services.
For more details, please check phone number attached eSIM.
Can I make calls with a data-only eSIM?
With a data-only eSIM, you cannot make or receive calls using a regular mobile phone line.
However, you can use app-based calls over the internet.
- LINE calls
- WhatsApp calls
- Messenger calls
- FaceTime
- Skype
- Zoom
- Google Meet
If you are only communicating with family and friends, using a data-only eSIM with calling apps may be sufficient.
However, if you need to call general phones such as hotels, restaurants, hospitals, or transportation, you may need a voice call compatible phone number attached eSIM.
Differences between regular calls and app calls
| Comparison Item | Regular Calls | App Calls |
|---|---|---|
| Line Used | Voice call line | Data communication |
| Phone Number | Required | Used for account registration |
| Recipient's Conditions | Can call general phones | May require the same app |
| Charges | May incur call charges | Consumes data |
| SMS | Available if supported by the plan | Not available |
| Emergency Calls | Available depending on line conditions | Often not available |
Who should consider a phone number attached eSIM?
- Those who want to call hotels or stores in Japan
- Those who want to make regular calls to business partners or workplaces
- Those who want to use a Japanese phone number as a contact
- Those who want to receive calls
- Those who want to receive SMS
- Those who want to use SMS authentication for certain services
- Those studying abroad or staying long-term
- Those who want to communicate with people who do not use apps
Who should consider a data-only eSIM?
- Those traveling to Japan for a short period
- Those whose main purpose is using Google Maps or social media
- Those who can communicate via LINE or WhatsApp
- Those who do not need a Japanese phone number
- Those who want to keep costs down
- Those who want to purchase and set up easily
- Those who can receive SMS on their primary overseas line
If you primarily use data communication, please check Japan eSIM products and pricing plans.
Checklist before purchasing a phone number attached eSIM
- Will a Japanese phone number be assigned?
- Does it support outgoing voice calls?
- Does it support incoming voice calls?
- What is the coverage for domestic and international calls?
- What are the call charges and free call duration?
- Does it support SMS reception and sending?
- Is identity verification required?
- What is the start date and validity period?
- Can the same phone number be extended?
- Can you call emergency numbers or toll-free numbers?
- What are the support methods and hours?
Do not judge solely by the label "with phone number"; check if it clearly states support for outgoing and incoming voice calls.
From purchasing to setting up a phone number attached eSIM
- Check if the device is compatible with eSIM
- Check if the SIM lock is removed
- Select a plan with a phone number attached
- Confirm support for outgoing and incoming voice calls
- Check call charges and SMS functionality
- Check the conditions for identity verification
- Purchase online
- Check the purchase confirmation email and QR code
- Add the eSIM in a stable Wi-Fi environment
- Confirm outgoing and incoming calls after starting use
You can check compatible devices from the list of eSIM compatible devices.
For detailed setup instructions, please refer to the eSIM setup guide.
Settings to check after arriving in Japan
Once you have set up the phone number attached eSIM, please check the following items:
- Turn ON the line for the phone number attached eSIM
- Check if you are connected to the network
- Select the eSIM to use for mobile data communication
- Set data roaming according to product instructions
- Set the standard voice line
- Make a test call
- Check incoming calls from another phone
- Check SMS reception if necessary
Please note that making test calls may incur call charges.
Make a short call to check the connection status.
Checklist if you cannot make calls
Check if it is a voice call compatible plan
Even if a phone number is displayed, you cannot make calls with products that are data-only or SMS-only.
Check the outgoing line
If you are using dual SIM, the primary overseas line may be selected instead of the phone number attached eSIM.
Check if the eSIM line is ON
If the phone number attached eSIM is disabled, you cannot make calls.
Check if signal is displayed
If it shows "out of service" or "searching," you are not connected to the network.
Check the method of entering the phone number
The method of entering the country code and the leading "0" differs between domestic and international calls.
Check the call balance
With chargeable products, you may not be able to make calls due to insufficient balance.
Check if it is an excluded phone number
Some products may not allow calls to emergency numbers, toll-free numbers, navigation numbers, or short numbers.
Restart the device
Please turn on airplane mode once and then turn it off, or restart your smartphone.
Checklist if you cannot receive calls
Check if it is an incoming call compatible plan
Products that are outgoing-only or forwarding service types may not support regular incoming calls.
Check the phone number
Please confirm that the caller is dialing the correct phone number.
Check the line and signal
If the eSIM line is OFF or out of service, you cannot receive calls.
Check call rejection settings
Please check if call rejection for unknown numbers or blocking of specific numbers is enabled.
Check do not disturb mode or focus mode
The call may not ring, and only notifications may remain.
Check forwarding settings
If call forwarding is set, calls may be forwarded to another number or voicemail.
Can I delete the eSIM if I cannot make calls?
Even if you cannot use the phone, do not delete the eSIM immediately based on your own judgment.
The QR code for the eSIM can only be used once, and if deleted, you may not be able to reconfigure the same line or phone number.
First, please check the following items:
- Voice call support of the purchased plan
- ON/OFF status of the eSIM line
- Line used for outgoing calls
- Network connection
- Call balance
- Method of entering the phone number
If you still cannot resolve the issue after checking, please contact Japan eSIM support before deleting.
For general connection issues, please also refer to troubleshooting for Japan eSIM connectivity issues.
Be aware of the expiration date of the phone number
With short-term use phone number attached eSIMs, the phone number may become unusable once the plan's validity period ends.
After the expiration date, the following functions may become unavailable:
- Making calls
- Receiving calls
- Receiving SMS
- Sending SMS
- SMS authentication for registered services
If you want to keep the phone number after your trip, please check if it can be extended or renewed before purchasing.
Be cautious when registering numbers for important services
If you register the phone number from a short-term eSIM with banks, credit cards, payment services, or social media, you may not be able to receive authentication codes after the usage period ends.
Additionally, there is a possibility that the phone number may be reassigned to another user after the contract ends.
If you have registered a short-term number, please change or delete the number before the end of the usage period.
Can I make emergency calls?
Even with a phone number attached eSIM, it is not guaranteed that you can make emergency calls to police, fire, or ambulance services.
Travel, prepaid, or roaming eSIMs may not be eligible for emergency calls.
Before purchasing, please confirm the support for emergency calls and prepare the following contact methods as well:
- Hotel front desk
- Travel agency support
- Local family or acquaintances
- Embassy or consulate
- Travel insurance company
Frequently Asked Questions about phone number attached eSIM calls
Can I definitely make calls with a phone number attached eSIM?
It is not guaranteed.
Please check if it is a plan that supports outgoing and incoming voice calls.
Can I make regular calls with a data-only eSIM?
Regular calls are not available.
Internet calls via LINE or WhatsApp are available.
Can I receive calls with a phone number attached eSIM?
You can receive calls if it is a plan that supports incoming calls and the line is active.
Are incoming calls free?
It varies by product and usage area.
While it may be free for domestic use, charges may apply while roaming abroad.
Can I select the line to use when making calls?
On dual SIM compatible devices, you can select the line to use when making calls or from device settings.
Can I make international calls?
You can use it if it is an international call compatible plan.
Please check the supported countries and call charges.
Can I call Japanese toll-free numbers?
Depending on the plan, you may not be able to call numbers like 0120.
Can I call emergency numbers?
It may not be available with travel eSIMs.
Please check the product specifications.
Can I use SMS with a phone number attached eSIM?
Even if it supports voice calls, it may not support SMS.
Please check the support for SMS reception and sending separately.
Can I use the internet while on a call?
It varies by device, communication method, and network.
If it supports VoLTE, you may be able to use data communication while on a call.
Can I use it simultaneously with the primary overseas line?
If you have a dual SIM compatible device, you may be able to activate both simultaneously.
If I delete the eSIM, will I lose the phone number?
If you delete it from the device, you will lose access to the line, and you may not be able to reinstall it.
Can I keep the same phone number after my trip?
With short-term plans, you may lose access after the expiration date.
Please check the conditions for extension or renewal.
For other questions, please refer to frequently asked questions about eSIM.
Summary | Check for outgoing and incoming voice call support before purchasing
With a phone number attached eSIM, if it is a plan that supports voice calls, you can make and receive calls from the standard phone app on your smartphone.
However, just having a phone number does not guarantee that calls can be made.
Depending on the product, there may be restrictions such as being data-only, SMS reception only, or incoming calls only.
Before purchasing, please check the following items:
- Does it support outgoing voice calls?
- Does it support incoming voice calls?
- Will a Japanese phone number be assigned?
- What is the coverage for domestic and international calls?
- What are the call charges and free call duration?
- Does it support SMS reception and sending?
- Can you call emergency numbers or toll-free numbers?
- What is the expiration date of the phone number?
- Can the same number be extended?
If you are traveling to Japan for a short period and primarily using maps, social media, LINE, or WhatsApp, a data-only eSIM may suffice.
If you want to make regular calls to hotels or stores, use work-related calls, or receive calls, choose a phone number attached eSIM that supports voice calls.
For details on phone number attached plans, please check phone number attached eSIM.
If you primarily use data communication, please check Japan eSIM products and pricing plans.
If you want to compare usage periods and data volumes, please check comparison of Japan eSIM pricing and plans.
