What is MNP?
Mobile Number Portability lets you change carrier and keep your phone number. Here is how it works and what it is not.
MNP (Mobile Number Portability) lets you move to a different carrier or brand and keep your phone number. In Japanese shops and advertisements it is commonly called 乗り換え (norikae, switching carrier). You begin the process with your current carrier.
MNP is not the other three procedures
- Operadora
- New
- Number
- Usually new
- Dispositivo
- Optional
- Operadora
- Same
- Number
- Same
- Dispositivo
- New
- Operadora
- Changes
- Number
- Kept
- Dispositivo
- Optional
- Operadora
- Same group
- Number
- Same
- Dispositivo
- Unchanged
The steps
- From your current carrier, get an MNP reservation number — or use one-stop MNP, where the new carrier pulls the details for you.
- Apply with the new carrier (online or in store) as an MNP customer, within the reservation number's validity.
- Choose a plan and, if you want, a device.
- Complete identity verification and payment setup.
- Activate the new SIM or eSIM. Your old line stops when the new one activates.
How to get your MNP number
You start this with your current carrier. One-stop MNP lets you skip the number entirely with participating carriers.
One-stop MNP (ワンストップ): with participating carriers you do not need a reservation number at all — you begin at the new carrier and authorise it to pull your details from the old one. Availability depends on both carriers and the route you use.
| Carrier / plan | Online | Phone | Shop |
|---|---|---|---|
| NTT DOCOMO one-stop MNP | My docomo → contract details → "MNP予約" (issue reservation number), or start one-stop MNP from the new carrier. | Call 151 / 0120-800-000 and follow the MNP menu. | Any DOCOMO shop can issue it (reservation may be needed). |
| ahamo one-stop MNP | In the ahamo / My docomo area, issue an MNP reservation number, or use one-stop MNP from the new carrier. | Not available as a phone procedure. | DOCOMO shops offer only paid assistance while you operate the site. |
| au (KDDI) one-stop MNP | My au → various procedures → MNP reservation, or one-stop MNP from the new carrier. | Call 157 / 0077-7-111 and follow the MNP menu. | au shops and some UQ spots can issue it. |
| povo2.0 one-stop MNP | Issue the MNP reservation number in the povo app, or use one-stop MNP from the new carrier. | Not available. | Not available — povo is not handled at counters. |
| SoftBank one-stop MNP | My SoftBank → issue MNP reservation number, or one-stop MNP from the new carrier. | Call 157 / 0800-919-0157 and follow the MNP menu. | SoftBank shops can issue it. |
| LINEMO one-stop MNP | Issue the MNP reservation number from the LINEMO / My Menu area, or use one-stop MNP from the new carrier. | Not available. | Not available. |
| Rakuten Mobile one-stop MNP | my Rakuten Mobile → issue an MNP reservation number, or use one-stop MNP from the new carrier. | Limited; use the app or chat. | Rakuten Mobile shops can help. |
| UQ mobile one-stop MNP | My UQ mobile → issue MNP reservation number, or one-stop MNP from the new carrier. | Call the UQ customer centre. | UQ spot and participating au shops. |
| Y!mobile one-stop MNP | My Y!mobile → issue MNP reservation number, or one-stop MNP from the new carrier. | Call 151 / 0570-039-151. | Y!mobile shops and participating SoftBank shops. |
Terms
Common questions
How do I keep my phone number when switching carriers in Japan?
Use MNP (Mobile Number Portability), commonly called 乗り換え. Either get an MNP reservation number from your current carrier, or use one-stop MNP where the new carrier pulls the details. Then apply with the new carrier as an MNP customer and activate the new SIM; your old line stops when the new one activates.
What is one-stop MNP?
With participating carriers you do not need a reservation number at all — you begin at the new carrier and authorise it to pull your details from the old one. Availability depends on both carriers and the route you use.
How long is an MNP reservation number valid?
Generally 15 days. The new carrier may require a minimum number of days remaining — some online routes require 10 or more. If it expires before you apply, issue a new one; issuing it does not cancel your current line.
Does MNP cost anything?
Issuing or using MNP is generally free, but the new carrier may charge its ordinary contract handling fee. If you use a carrier email address, check that carrier's paid address-carrying service and its deadline before switching.
When does my old line stop working?
When the new SIM or eSIM activates. Until then the old line stays active, so you are not left without service during the switch. Activation is a step you complete yourself after the new SIM arrives or the eSIM profile is issued.