Frequently asked questions before applying for J:COM MOBILE

We introduce frequently asked questions from customers.
If you have any questions, please contact us by phone or chat.

User MOBILE support

About contracts and fees

Procedures such as contracting and changing models are cumbersome.

You can apply easily from the website. Free support is also available upon request.

You can apply for J:COM MOBILE online. You can complete the process from the comfort of your own home, so there is no need to go to a store and wait for a long time.
Once you receive your smartphone, you can receive free support if you wish. We will provide detailed instructions on how to use your smartphone, as well as the initial settings.

About initial setup support

Those applying for "J:COM MOBILE D Plan SIM Card" are not eligible.

Can I apply for multiple lines?

A maximum of 5 lines can be subscribed to under one contract name.

What happens to the name of the contract if my family members have separate contracts for lines?

The contract name will be the same.

Only eSIM (A plan SU) can be contracted under a separate name. However, you may not be able to receive benefits such as Date Mori.

For example, if you have a contract with J:COM in your husband's name.

  • Your husband has a contract with Company A → MNP to J:COM MOBILE
  • Contract with D company in wife's name → MNP to J:COM MOBILE
  • Contract with S company in your child's name → MNP to J:COM MOBILE

In this case, both the wife and children are contracted in the name of the master.

I have a contract for multiple lines in my family. Can my family pay the monthly usage fee separately?

You cannot pay separately.

Only one type of payment information is required to be registered at the time of contract.

Can I subscribe to J:COM MOBILE no matter where I live in Japan?

J:COM MOBILE can now be applied for nationwide from September 17, 2020.

You can also use this service even if you live outside of J:COM 's cable TV service area.

I am using J:COM for the first time. Can I sign a contract for only J:COM MOBILE?

Yes, you can subscribe to J:COM MOBILE alone.

You can check it easily from the smartphone charge simulation, so please try it.

Is there an examination at the time of contract?

J:COM will conduct a membership screening when accepting contract applications. Please note that we may not be able to accept your application depending on the results of the screening.

About data migration

Can I continue to use LINE on my new device?

By completing the appropriate settings and procedures, you can continue to use the service on your new device.

Regarding account migration (handover) procedures, security is regularly strengthened, so please check the latest information on LINE's official blog before proceeding.
(*Please note that settings may be required before changing the model)

How to transfer your LINE account (as of July 2017)

I want to transfer data such as my phone book to a new smartphone, what should I do?

Solve difficult settings at home. Leave the initial settings of your smartphone to "remote control"!

J:COM MOBILE provides free support that provides detailed instructions on initial settings, migration of phonebook data, instructions on how to use the service, etc. for those who wish to do so.

Click here for details

Can I continue to use the email address I'm currently using on my J:COM MOBILE smartphone?

If you are using a free email service such as Gmail, you can continue to use it by logging in or setting up a new device.

Please note that if you are using an email address (domain) issued by some telecommunications companies, you will not be able to use it.

There are some services that allow you to continue using carrier mail even after canceling your carrier. Please refer here for details.

J:COM MOBILE does not issue email addresses, so we recommend that you switch to a free email such as G-mail in advance.

About communication and data

What is the communication area of J:COM MOBILE? I'm worried about whether it will connect properly.

J:COM MOBILE A Plan line is the same as au. You can connect without problems even in the suburbs or the city center.

J:COM is part of the same group as major carrier au. J:COM MOBILE A Plan uses the au line, and the communication and calling areas will also follow this.

Click here for details

Can I carry over unused data usage?

Unused data traffic will be automatically carried over to the next month.

*The remaining amount is valid until the end of the following month.

If the upper limit is exceeded, the speed will be limited to 1Mbps or 200kbps depending on the plan you subscribe to. In addition to the data usage of your contract plan, you can also carry over any additional data usage you purchase to the next month.

Please check here for details such as the expiration date.

What happens if I exceed my data usage limit?

If you exceed the upper limit, it will be limited to 1 Mbps or 200 kbps depending on your subscription plan.

If the total amount of data used in the current month exceeds the monthly data volume (including additional data and carry-over data), the communication speed will be restricted as follows until the end of the month.

  • Customers with a 10GB/20GB contract: maximum transmission/reception of 1Mbps
  • Customers with a 1GB/5GB contract: maximum transmission/reception of 200kbps

However, if you want to return to normal speed, you can purchase additional data. You can check the remaining data capacity in the app.
Please see this page for details.

Can J:COM MOBILE smartphones be used overseas?

Calls can be used overseas, but data communication is not available.
Please use Wi-FI for email and internet connection.

J:COM MOBILE can be used overseas with the "International Roaming Service (au World Service)" for calls and SMS only.
Mobile data communication is not available overseas, so if you want to use email or the Internet overseas, please use an overseas Wi-Fi router or local Wi-Fi connection service.

Click here for details on how to use overseas

PR Wi-Ho!, where you can rent a Wi-Fi router for overseas use!
Click here for details

About options

Can I use tethering?

It supports tethering.

Terminals handled by J:COM MOBILE support tethering.

What kind of SD card should I prepare?

Please purchase a "microSD card". At J:COM MOBILE, you can purchase it at the time of purchasing a "device".

J:COM MOBILE sells microSD cards with a capacity of 128GB as an accessory.
If 128GB is not enough for you, you can purchase it at electronics retailers, but the types of microSD cards that can be used and the maximum capacity differ depending on the model.
When making a purchase, please show the following information to the store staff so that your purchase can go smoothly.

  • <Supports up to microSDXC 1TB>
    BASIO active/Galaxy A23 5G/AQUOS wish/AQUOS sense6s/Galaxy A21/AQUOS sense5G
  • <Supports up to microSDXC 512GB>
    AQUOS sense3/Galaxy A30/Galaxy A20/Galaxy Tab A/BASIO4
  • <Supports up to microSDXC 256GB>
    AQUOS L2/HUAWEI P20 lite/BASIO3/HUAWEI MediaPad T5
  • <Supports up to microSDXC 200GB>
    LG X screen/arrows M03/LG G Pad 8.0 III
  • <Supports up to microSDXC 128GB>
    HUAWEI P10 lite/LG G Pad 8.0 L Edition/Xperia Z2 Tablet
  • <Supports up to microSDHC 32GB>
    LG Wine Smart/arrows M02

We do not guarantee the operation of any accessories other than those handled by J:COM MOBILE. Please note.

Does J:COM MOBILE have an "Unlimited calls" plan?

We offer an optional flat-rate call service, “Unlimited calls”.

With this service, domestic calls of up to 5 minutes or 60 minutes are free of charge as many times as you like.

Click here for details on "Unlimited calls"

Can I use Unlimited calls with any plan?

Unlimited calls is only available to subscribers of J:COM MOBILE A Plan.

It cannot be used with J:COM MOBILE D plan SIM Card. Please note.

What kind of warranty and support system do you have in case of terminal failure or loss?

We offer a wide variety of options, from free repair services to warranty options in preparation for unexpected troubles such as dropping, submersion, and loss of devices.

In the case of a terminal failure, if it is within a certain period of time after purchasing the terminal and the failure is natural, we will repair it free of charge.

If a certain period of time has passed after purchase, it will be charged. Click here for the free warranty period for each product

If you want to prepare for troubles that cannot be covered by repairs or the loss of your device, you can use the paid option "Safe Terminal Warranty 48", "Device Warranty for iPhone" for au Certified iPhones (certified second-hand goods), and "AppleCare+" for iPhones. for iPhone" is recommended.

Additionally, if you are looking for more comprehensive support, we recommend Enkaku Support, where you can consult with specialized staff as many times as you like for J:COM TV, NET, etc.
Please refer to the following for more information.

About 5G

What is 5G?

It is the 5th generation mobile communication system, which is the next generation of 4G.

For details, please check here.

How can I use the 5G service?

The following three items are required to use 5G service with J:COM MOBILE.

  1. Make a 5G contract with J:COM MOBILE A plan (voice + data)
  2. Please prepare a 5G compatible device Click here for J:COM MOBILE's device lineup
  3. Communication within the 5G communication area
Is there a charge for using the 5G service?

No, there are no additional charges for using 5G service.

Where is the coverage area for 5G service?

Please check the 5G service coverage area here.

5G services have been launched on a limited basis initially. Therefore, depending on the customer, communication with 4G services will be the main focus.

Which devices are 5G compatible?

If you are purchasing a device from J:COM MOBILE, please check here.

If you purchase a device other than J:COM MOBILE, please check whether 5G service is available. Please note that this service may not be available depending on your device.

How do I apply for the 5G service?

Those who newly subscribe to the J:COM MOBILE A plan will automatically be able to use the 5G service, so there is no need to apply separately.

[Customers who have already subscribed to J:COM MOBILE]

If you signed up for J:COM MOBILE before August 25, 2021, you will need to apply separately to use the 5G service. Please contact the customer center for details.

Changes to 5G service

Will there be any fees when changing to 5G service?

No fees will be charged for changing to 5G service.

Can I still use the SIM?

Yes, if you are a J:COM MOBILE subscriber and change your service to 5G, you can use the same SIM Card to use the 5G service.

Limited to J:COM MOBILE A plan (voice + data) subscribers.

5G communication requires a 5G terminal.

What should I do if I want to change to 5G service?

You can switch to 5G from My Page.
Log in with J:COM Personal ID → Select "Smartphone" from the service menu → Click the 5G service application button to complete the procedure.

How soon will I be able to use the 5G service after applying?

If you apply online, the switch will be performed sequentially from 9:00 a.m. two days after your application.

[About the amount including tax]

  • Consumption tax differences may occur due to changes in the consumption tax rounding method under the invoice system.