Getting a Japanese phone number is one of the first things you should consider doing after arriving in Japan. A Japanese number can be useful for setting up bank accounts, making reservations, receiving deliveries, registering for services and, of course, keeping in contact with people in Japan.

These days, you do not necessarily need to buy a new phone. If you already have an unlocked smartphone that works with Japanese mobile networks, the easiest and cheapest option will often be to keep your current phone and sign up for a SIM-only plan.

SIM-Only Plans

A SIM-only plan gives you Japanese mobile service without purchasing a new phone.

Depending on your phone, you can normally choose between:

Physical SIM – A small SIM card that you insert into your phone.

eSIM – A digital SIM that can be downloaded directly onto compatible smartphones.

SIM-only plans are available from the major mobile companies as well as cheaper online/mobile providers.

Some popular options include:

• Rakuten Mobile
• ahamo (NTT Docomo)
• povo (au)
• LINEMO (SoftBank)
• Y!mobile
• IIJmio

Prices, data allowances and special offers change frequently, so check each company’s website before applying.

Before applying

Make sure that:

• Your phone is SIM unlocked
• Your phone supports Japanese mobile frequencies
• Your phone supports eSIM if you plan to use one
• You have a valid Japanese address
• Your residence card information is up to date

If you brought your phone from overseas, it is also worth checking whether the model is officially compatible with the network you want to use.

Applying in Person

For new arrivals, applying at a mobile phone shop can often be the easiest option.

This is particularly useful if you are having trouble with online identity verification, have recently received a new residence card, or would simply prefer someone to help you through the application.

You can apply at carrier shops such as:

• Rakuten Mobile
• Docomo
• au
• SoftBank
• Y!mobile

Some electronics stores also have mobile-phone counters where contracts and SIM cards can be arranged.

What should I bring?

Requirements vary depending on the company, but you should generally bring:

• Your residence card (在留カード / Zairyu Card)
• Your passport
• A Japanese credit or debit card, if you have one
• Your Japanese bank account details or bank book, if you want to pay by direct debit
• Your current phone, particularly if you are signing up for a SIM-only plan
• Your My Number Card, if you have one

Make sure the name and address on your residence card match the information you give to the mobile company.

Some companies may also have requirements relating to how much time remains on your period of stay.

If your Japanese is limited, having someone who speaks Japanese accompany you can make the process considerably easier. Some larger stores may also have English-speaking staff or translation services available.

Applying Online

Many mobile providers now allow the entire application to be completed online.

This can often be cheaper and faster than applying in a store, particularly with online-focused services such as ahamo, povo, LINEMO and IIJmio.

You will normally:

1. Choose your plan.
2. Choose a physical SIM or eSIM.
3. Enter your personal information.
4. Complete an online identity check.
5. Enter your payment details.
6. Wait for your application to be approved.
7. Receive your SIM by post or activate your eSIM.

What will I need?

You will generally need:

• Your residence card
• Your passport, depending on your residence status/provider
• A smartphone with a camera
• A smartphone capable of reading NFC/IC chips for providers that use this form of identity verification
• A Japanese address
• An email address
• A compatible payment method
• Your current mobile number and MNP information if you are transferring an existing Japanese number

Some online applications require you to scan the IC chip inside your residence card and/or take a photograph of yourself to confirm your identity.

The exact process is different for each company, so carefully check the provider’s identity-document requirements before starting your application.

Important: New Second-Generation Residence Cards

Japan introduced a new format of residence card from June 14, 2026.

If your residence card was issued on or after this date, you may have a second-generation residence card (第二世代在留カード) or one of the new cards connected with the My Number system.

These new cards have caused some problems with online mobile-phone applications because mobile companies have had to update their identity-verification systems to recognise the new card format.

You can check the current information on the following site:

https://setupinjapan.com/residence-card/online-verification/

Whether you can apply online currently depends on the mobile provider.

Some companies have already updated their systems, while others still do not support the new cards through certain online verification methods.

For example, Rakuten Mobile introduced online support for second-generation residence cards in September 2026. Other services may still require a different verification method or may not yet accept the cards online.

Choosing a Provider

There is no single “best” mobile provider for everyone.

When comparing plans, consider:

Data
How many GB will you actually use each month?

Coverage
Most providers have very good coverage in populated areas, but coverage can differ in rural and mountainous areas.

Price
SIM-only plans can be significantly cheaper than traditional phone contracts.

English support
Some companies provide much more English-language information and support than others.

Contract conditions
Check cancellation rules and any fees before signing up.

International calling
If you regularly call home, check international calling prices. However, apps such as LINE, WhatsApp, FaceTime, Messenger and similar services mean that traditional international phone calls are rarely necessary.

Bringing a Phone from Home

Bringing an unlocked smartphone from your home country is now a very practical option.

Before arriving in Japan, check:

• Whether the phone is SIM unlocked
• Whether it supports a physical SIM, eSIM, or both
• Whether the Japanese carrier you are considering lists your phone as compatible

Once you have confirmed compatibility, you can simply sign up for a SIM-only plan and continue using your existing phone.

A Final Tip

Mobile-phone plans and promotions in Japan change regularly.

Rather than choosing a company based only on information you find in an old guide, check the provider’s current website shortly before applying.

And if an online application keeps rejecting your brand-new residence card, try applying at a physical shop instead, it may be the verification system, not something you are doing wrong.