SIM vs eSIM in Japan: Can I Use My Phone Here?

Rakuten Mobile Employee Referral Guide日本語

By Mirai, Rakuten Mobile employee · Not the official Rakuten Mobile website

You live in Japan and you want a cheaper phone plan. You see two words: SIM and eSIM. Which one should you choose?

This guide explains the difference in simple English. It also shows how to check if your current phone can work in Japan.

What is a SIM card and what is an eSIM?

A SIM is the small chip that connects your phone to a mobile network. Without it, you cannot call or use mobile data.

A SIM card is a physical card. You put it inside your phone. Rakuten Mobile offers it in three sizes: nano, micro, and standard.

An eSIM is a digital SIM. There is no card. You download the line information into your phone.

Both give you the same plan and the same network. The difference is how you receive the SIM.

SIM card or eSIM: which is faster?

Speed is often the biggest difference for new users in Japan.

• SIM card in a shop: you get the card on the spot.
• SIM card online: Rakuten Mobile says it is shipped within 2 days. Delivery may take several days to a week.
• eSIM: there is no delivery. You set it up on your phone.

If you apply in the app with a compatible eSIM device, you can use Simple Mobile ID Verification. With this method, screening can finish in as little as 3 minutes.

For identity verification documents, foreign nationals can use a residence card or a Special Permanent Resident Certificate.

A simple comparison

Fees may change. Please check the Rakuten Mobile website for the latest information.

Does my phone support eSIM?

Not every phone supports eSIM. Rakuten Mobile says eSIM is supported by iPhone XS, XR, and newer models, and by the latest Android smartphones.

The list of eSIM-compatible models that were sold before is marked “As of July 2026”. So the list can change over time.

If your phone does not support eSIM, that is fine. You can simply choose a physical SIM card instead.

Can I use the phone I already have?

Many international students bring a phone from their home country. Sometimes it works in Japan, and sometimes it does not.

Here are the three things to check.

1. Is your model on the compatibility list?

Use the device checker on the Rakuten Mobile website. You can choose a category:

• Apple
• Android smartphone
• Tablet
• Mobile Router
• PC

The checker shows which functions are supported for your model.

2. Was the phone bought overseas?

This is very important. Rakuten Mobile says that even if a device is listed as compatible, it may not be usable if you bought it overseas.

In Japan, phones need the Japanese Technical Regulations Compliance mark. People often call it the “giteki” mark. A device without this mark may be refused connection to the network.

You can often find the mark in your phone settings, in the legal or certification information screen. If you are not sure, ask at a Rakuten Mobile shop.

3. Is your phone SIM locked?

A SIM lock means the phone only works with one carrier. Devices bought before October 2021 may need a “SIM unlock” procedure.

On an iPhone with iOS 14 or newer, you can check like this:

1. Open Settings.
2. Tap General.
3. Tap About.
4. Look at SIM Lock. “No SIM restrictions” means there is no lock.

Devices bought at Rakuten Mobile are SIM-free. For other brands and Android models, ask the shop or carrier where you bought the phone.

Which one should you choose?

There is no single right answer. Think about your own situation.

• Choose eSIM if your phone supports it and you want to start quickly.
• Choose a SIM card if your phone has no eSIM support, or if you often move your SIM between phones.
• If you are not confident with the setup, going to a Rakuten Mobile shop is a good idea.

Note one small point. Reissuing a physical SIM card costs 3,300 yen including tax, but an eSIM reissue is 0 yen (as of October 2026).

Rakuten Mobile has English pages, and you can apply online in English.

Do the referral login before you apply

Mirai is a Rakuten Mobile employee. She shares an employee referral link for the Rakuten SAIKYO Plan and Rakuten SAIKYO U-NEXT.

The referral login is the entry from the referral link. It is free. You just log in with your Rakuten ID. It does not sign you up for any plan.

Here is the basic order:

1. Do the referral login first, with your Rakuten ID.
2. Check your device with the device checker.
3. Apply for the plan with the same Rakuten ID.
4. Start using the line.
5. Make a call of 10 seconds or more with the Rakuten Link app.

Points are 14,000 per line with an MNP transfer. MNP transfer means keeping your phone number when you switch. In other cases, such as a new number, points are 13,000.

You must finish three things in time. These are the application, the line start, and the Rakuten Link call.

The deadline is 23:59 on the last day of the second month after your entry day. For example, if you enter in September, the deadline is November 30.

Rakuten Points from this campaign are time-limited points. The conditions may change, so check the details after you do the referral login.

Summary

• A SIM card is physical; an eSIM is digital and needs no delivery.
• Check your model with the device checker on the Rakuten Mobile website before you apply.
• A phone bought overseas may not work, even if the model looks compatible, because of the Japanese Technical Regulations Compliance mark.
• Do the referral login first, then apply with the same Rakuten ID, and make a 10-second Rakuten Link call.

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