The simplest way to plan your phone when you are posted abroad from Japan is to treat "how to keep your Japanese number" and "when you can get a local line" as two separate decisions, and take them in order. For your Japanese number you can keep the contract, put the number into storage, or cancel it. But docomo and au both state that while a number is in storage, calls and SMS stop working. If your bank or online services send verification codes to that number, you need to move those codes somewhere else before you store it. A local contract in your new country, meanwhile, often requires an ID issued locally, such as a work pass, so you may not be able to sign up on the day you arrive. This article uses official information from carriers and government bodies to lay out the order, from before departure to your return.
Between arriving and getting a local contract, you can stay online with a travel eSIM that you set up before leaving. Choose a plan for your destination from Coral eSIM's plan list.
An expat phone plan has two parts: your Japanese number and a local line
Two lines with different jobs are involved in the phone you use on assignment.
- Your Japanese number: the contact point for Japanese banks, logins to government and other services, and calls from family and business contacts in Japan
- A local line: calls and data in your new country, and the number you give to local banks and your employer
docomo lists four options for people going abroad for work or study: keep the Japanese contract and use it abroad, buy a local SIM card, use its number storage service, or cancel. It suggests keeping the Japanese contract for short stays and using a local SIM card for stays of three months or more. An overseas posting is a long stay, so plan on having a local line and decide what to do with your Japanese number.
| Japanese number | SMS (verification codes) | Suits people who |
|---|---|---|
| Keep the contract | Received abroad (roaming) | Keep using Japanese banks and services with SMS verification |
| Store the number | Not received during storage (stated by docomo and au) | Want to keep the number but will not use the Japanese line abroad |
| Cancel | Not received; the same number cannot be used after returning | Have nothing tied to the Japanese number |
docomo explains that SMS is received automatically abroad and works in any country or region where calls are available, even outside its data coverage. In other words, if you want to keep receiving SMS on your Japanese number, you need to keep the contract, not store it.
Before you leave: the conditions for storing your Japanese number
Japan's three major carriers each offer a service that holds your number while you are not using your phone because of an overseas posting or study. The conditions differ.
| Carrier | Service | Maximum storage | Main conditions |
|---|---|---|---|
| docomo | Phone number storage | Up to 6 years from the 1st of the month after you apply | Apply online, by phone or in store. ahamo and some plans are excluded. Cannot be booked in advance |
| au | Temporary suspension | Up to 5 years | Apply via My au, chat or in store. Reactivation in store only. UQ mobile excluded |
| SoftBank | Phone number and email address storage | Up to 5 years | Apply at a SoftBank shop with ID |
For Rakuten Mobile, we could not find a similar number storage service on its official website.
Apply right before you leave
docomo states that calls and data stop the moment you apply, and you cannot book the storage in advance. If you want it to start when you leave Japan, it recommends applying through its online procedures shortly before departure. Apply too early and your Japanese number will not work for the days before your flight. SoftBank requires a shop visit, so book one before departure.
Storage ends in automatic cancellation
docomo states that when the storage period ends, the contract is cancelled automatically and the number cannot be used again. To continue, you must release the storage and apply again before it expires. SoftBank also ends the contract after the period, and says it does not send advance notice. Postings get extended, so put the expiry date in your calendar.
Move your SMS verification before storing your number
The biggest trap with number storage is verification codes. au says phone, internet, email and SMS cannot be used during a temporary suspension. docomo states that if your d ACCOUNT security codes go to your phone number, you cannot receive them during storage, and that you need to set up passkey authentication before storage to log in to My docomo.
The same applies to any bank or online service that sends codes by SMS to your Japanese number. Before applying for storage, work through these steps.
- List the services that use SMS verification on your Japanese number (banks, brokers, credit cards, government services, shopping, social media)
- For each one, check whether you can switch to an authenticator app, a passkey, email or another method that is not SMS
- If some services cannot be switched, consider keeping the contract instead of storing the number
- Make sure you can still log in to your carrier account itself (for docomo, set up a passkey)
For why codes fail to arrive while travelling and what to do, see what to do when SMS verification codes do not arrive abroad.
Right after arrival, bridge your expat phone plan with a travel eSIM
A local phone contract may require an ID issued in your new country. For example, Singtel's online plan "hi!" in Singapore lists a Singpass account (Singapore's digital ID for government services), or an ID such as an Employment Pass or Dependent Pass, as a sign-up requirement. Until your work pass is processed, you cannot start a contract like this. Requirements vary by country and carrier, so check your destination carrier's official website.
For data in the meantime, you can use a travel eSIM set up in Japan. Apple describes keeping both your home line and a travel line active while travelling, and assigning only cellular data to the travel line. That way your Japanese number stays on for calls and SMS, while maps, ride-hailing and flat-hunting run on the eSIM's data. For the steps, see how to set up an eSIM for travel.
Also note that Japanese nationals living abroad for three months or more are required by the Passport Act to submit a Residence Registration (zairyu todoke). According to Japan's Ministry of Foreign Affairs, you can submit it from three months before leaving Japan. It also brings emergency email alerts, so do it before you go.
Find an eSIM for your destination in Coral eSIM's plan list.
One phone for a local line and your Japanese number: dual SIM for expats
If you keep your Japanese number after getting a local line, putting both lines in one smartphone saves carrying a second device. According to Apple, iPhone XS, XR and later support two lines with a physical SIM and an eSIM, and iPhone 13 and later also support two eSIMs. Both numbers can make and receive calls and SMS, but only one line can be used for cellular data at a time.
Apple also notes conditions that matter for people on assignment.
- To use lines from two carriers, your iPhone must be carrier-unlocked (how to check if your phone is unlocked)
- If you have a corporate plan, check with your company administrator that it supports two lines
- In mainland China, only some iPhone models support eSIM
The role of each line changes with each stage of the posting.
| Stage | Japanese number | Data |
|---|---|---|
| Before departure | Sort out where codes go. If storing, apply before leaving | Set up a travel eSIM in Japan |
| Right after arrival | If kept, use it to receive SMS | Travel eSIM |
| After the local contract | If kept, leave it as a secondary line | Switch to the local line |
| Before returning | Check how to release the storage | Local line until you leave |
For dual SIM setup on iPhone and Android, see our dual SIM setup guide for travel.
Prepare your expat phone plan for home visits and your final return
If you store your number, plan for how you will reactivate it when you come back.
- docomo: after releasing the storage you keep using your current docomo UIM card, so it asks you to keep the card safe
- au: reactivation is in store only, and you need the application receipt, ID and the phone itself
- SoftBank: you cannot release storage in the same billing month you stored it, and cannot store it again in the month you released it
SoftBank's conditions do not suit using your number only during a short home visit. For data while visiting Japan, you can also use a Japan eSIM.
Expat phone plan: frequently asked questions
Can I receive SMS on my Japanese number while posted abroad?
Yes, if you keep the contract. docomo says SMS is received automatically abroad and works in countries and regions where calls are available, even outside data coverage. If you use docomo's number storage or au's temporary suspension, however, calls and SMS stop for that period.
How far ahead of departure should I apply for number storage?
docomo does not accept advance bookings and stops calls and data as soon as you apply, so it recommends applying online shortly before you leave. SoftBank requires a shop visit, so fix the date first. In every case, move your verification codes before you apply.
What happens when number storage expires?
docomo cancels the contract automatically at the end of the storage period, and the number cannot be used again. SoftBank also ends the contract after the period, without advance notice.
Can I get a local phone contract as soon as I arrive?
It depends on the country and carrier. For example, Singtel's hi! in Singapore requires a Singpass account or an ID such as an Employment Pass or Dependent Pass. Until your pass is ready, a travel eSIM set up in Japan keeps you connected.
Can I use my Japanese number and a local number on one iPhone?
Yes. According to Apple, iPhone XS, XR and later can use a physical SIM and an eSIM, and iPhone 13 and later can use two eSIMs. To use lines from two carriers the phone must be unlocked, and only one line can carry data at a time. For corporate plans, check with your administrator.
Decide where your SMS codes will go before choosing what to do with your number
The usual mistake with an expat phone plan is thinking only about whether to keep your Japanese number. In practice, storing the number stops calls and SMS, and verification codes from Japanese banks and services stop arriving. Sort out where your codes go first; keep the contract if you still need SMS, and store the number right before departure if you do not. Get a local line once you have your residence ID, and bridge the gap with a travel eSIM until then. In that order, you stay reachable from the day you arrive until the day you return.
See plans for your destination in Coral eSIM's plan list.
