What Is MNP Transfer in Japan? Keep Your Phone Number

Rakuten Mobile Employee Referral Guide日本語

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

Do you want to change your mobile carrier in Japan? You do not need to change your phone number.

The system for this is called MNP transfer (keeping your phone number when you switch carriers). This guide explains it in simple English.

First: do you already have a Japanese phone number?

This guide is for people who already have a Japanese mobile number. For example, you have a contract with another carrier now.

If you just arrived in Japan and have no Japanese number, MNP is not for you. You simply apply as a new customer and get a new number. That is fine, and you can still join the employee referral campaign.

Also, you cannot move a phone number from your home country to Japan. MNP works only between Japanese carriers.

What does MNP transfer mean?

MNP means you leave your old carrier and join a new one. Your phone number stays the same.

• Your friends, your bank and your school can still call the same number.
• Your old contract ends when the transfer finishes.
• Your old SIM (the card or profile that connects your phone to the network) stops working.

Important: the name on your old carrier contract and the name on your Rakuten Mobile contract must be the same person. If the names are different, the transfer does not work.

Two ways to do MNP

1. MNP One Stop

With MNP One Stop, you do not need to ask your old carrier for anything first. You start everything from the new carrier’s application.

Many carriers support One Stop. The list includes NTT docomo, au, SoftBank, ahamo, UQ mobile, povo, Y!mobile, LINEMO, mineo and IIJmio, and more.

You cannot use One Stop in these cases:

• Your old carrier is not on the One Stop list.
• You already got an MNP Reservation Number.
• You apply at a shop.

2. MNP Reservation Number

An MNP Reservation Number is a number you get from your old carrier. You give it to the new carrier.

You need it when your old carrier does not support One Stop. You also need it for any application at a shop, even if your old carrier supports One Stop.

For an online application, the reservation number must still have 7 days or more left before it expires. If there are fewer days left, get a new one.

Timing: when does the number move?

The change of your number to the new carrier happens at set times.

After that, you activate the line yourself. If you do this between 9:00 and 21:00, it finishes the same day.

Do not forget to activate. If you never do it, the line switches automatically at 10:00 on the expiry date of the reservation number. Your billing starts from then.

The MNP transfer-out fee is 0 yen (as of October 2026).

MNP and the employee referral campaign

I am a Rakuten Mobile employee. This page is my personal guide, not an official Rakuten page.

With the employee referral campaign, people who keep their number by MNP get more points.

• 14,000 Rakuten Points per line for an MNP transfer.
• 13,000 Rakuten Points in other cases, such as a new number.

The plans covered are Rakuten SAIKYO Plan and Rakuten SAIKYO U-NEXT. Up to 5 lines per person are covered. People who used Rakuten Mobile before and cancelled are also covered. Applications at shops are covered too.

Points come in three parts. For MNP: 5,000 → 5,000 → 4,000. For other cases: 5,000 → 4,000 → 4,000.

The points start 4 months after the month of your referral login (your entry from the referral link), over three months. They are Rakuten Points (time-limited points) and are valid for 6 months, including the day you get them.

The order is important

Many people lose the points because of the order. Please read this part carefully.

1. Referral login first. Log in with your Rakuten ID from the referral link. It is free. It does not sign you up for any plan.
2. Then apply for Rakuten SAIKYO Plan or Rakuten SAIKYO U-NEXT. Use the same Rakuten ID. A different ID is not counted.
3. Start using the line (your plan usage start date).
4. Make one call of 10 seconds or more from the Rakuten Link app.

An entry within 7 days including your application day may still be accepted. But you may be asked to confirm it. Entering first is safer.

All four steps must finish by 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. Applying alone is not enough.

For the 10-second call, you can call a family member or your own other number. These calls are not counted:

• Numbers starting with 0570
• Numbers with #
• Calls with a prefix number
• Special numbers such as 188

Prices and English support

Rakuten SAIKYO Plan for one person (tax included, standard price, as of October 2026):

• Up to 3GB: 1,078 yen
• Up to 20GB: 2,178 yen
• Over 20GB (unlimited): 3,278 yen

Rakuten SAIKYO U-NEXT is 4,378 yen (as of October 2026). The contract fee is 0 yen up to the 4th line (as of October 2026). Prices may change.

Rakuten Mobile has English pages and you can apply online in English. Note that the MNP guide page is in Japanese only.

Some details are not written here. Examples are identity verification documents (papers that show who you are), payment methods and shop steps. Please check the Rakuten Mobile website for these points. You can also ask at a Rakuten Mobile shop.

The campaign may change or end without notice. Please check the latest conditions after your referral login.

Summary

• MNP transfer lets you keep your Japanese phone number when you change carrier.
• Use MNP One Stop, or get an MNP Reservation Number with 7 days or more left.
• The name on both contracts must be the same, and you must activate the line yourself.
• Do the referral login first, then apply, start the line, and make a 10-second Rakuten Link call before the deadline.

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