If you're preparing to leave Japan, figuring out what to do with your Japanese mobile phone plan is one of those practical tasks that's easy to forget until the last minute. Whether you're leaving for good, heading home for a few months, or planning to return, your options are different — and the wrong choice can mean losing your number or paying fees you didn't expect. This guide walks you through everything you need to know about leaving Japan mobile phone plan decisions, step by step.
Your Three Main Options When Leaving Japan
Before diving into the details, it helps to understand the three paths available to you:
- Cancel your contract entirely — best if you're leaving permanently and don't need the number again.
- Port your number (MNP) to a different carrier or plan — useful if you want to keep your Japanese number on a cheaper or more flexible plan.
- Suspend or keep your contract temporarily — possible with some carriers if you plan to return to Japan.
Which option makes sense depends on how long you're leaving, whether you'll return, and how important your Japanese phone number is to you. Let's look at each one.
Cancelling Your Japanese Mobile Contract
When cancellation makes sense
If you're leaving Japan permanently, or you're sure you won't need a Japanese number again, cancelling your contract is usually the simplest choice. Keep in mind that once you cancel, your phone number is gone for good — you cannot reclaim it later.
How to cancel: general steps
- Check your contract terms first. Some plans have minimum contract periods or early cancellation fees. Log in to your carrier's app or website, or visit a store, to confirm your current contract end date and any fees that apply.
- Choose your cancellation method. Most major carriers (docomo, au, SoftBank) allow cancellation in-store or online. Bring your residence card, your device, and any documents related to your account.
- Set your cancellation date carefully. Billing is usually monthly, so timing your cancellation to fall at the end of a billing cycle can help you avoid paying for an extra month.
- Return any rental devices or SIM cards as required by your carrier.
- Confirm in writing. Ask for a cancellation confirmation number or email for your records.
Fees, timing rules, and procedures vary by carrier and plan — always confirm the latest details on your carrier's official website or at a store before you proceed.
Number Portability (MNP): Keeping Your Japanese Number
What is MNP?
MNP stands for Mobile Number Portability. It lets you move your existing Japanese phone number to a different carrier without losing it. This is worth considering if you want to downgrade to a cheaper plan before leaving, or if you want to switch to a more foreigner-friendly provider.
How to use MNP
- Request an MNP reservation number (MNP予約番号) from your current carrier. You can usually do this online, by phone, or in-store. This number is valid for a limited period (typically around 15 days — confirm with your carrier).
- Apply to your new carrier using that reservation number before it expires.
- Complete your new carrier's sign-up process. Requirements vary; some carriers need a Japanese credit card and bank account, while others are more flexible.
If you're switching to a lower-cost plan before departure, foreigner-friendly MVNOs (Mobile Virtual Network Operators) like GTN Mobile are worth considering — they accept a residence card and offer multilingual support, which is helpful if your Japanese is limited. Always check the latest plan details and requirements on their official site, as offerings change.
Temporary Suspension: An Option If You're Coming Back
If you're leaving Japan temporarily — for example, returning home for a few months — some carriers offer a contract suspension service. During suspension, you typically don't pay your full monthly fee, but you may pay a small holding fee, and your number is preserved.
- Not all carriers or plans offer this option, and conditions differ widely.
- There is usually a maximum suspension period.
- You may need to visit a store or call customer service to arrange it.
Check directly with your carrier whether suspension is available on your plan and what the exact conditions are.
What About Prepaid SIMs and Short-Term Options?
If you're returning to Japan in the future — even just for a visit — a prepaid SIM or eSIM can be a convenient, no-commitment solution. You can purchase these at airports or convenience stores, or order an eSIM online before you arrive. They require no long-term contract and are ideal for short stays.
For longer return visits where you need a full contract SIM again, remember that you'll generally need a valid residence card and a Japanese address. Providers like GTN Mobile and Mobal are known for being accessible to foreigners — GTN Mobile accepts a residence card and offers flexible payment options, while Mobal does not require a Japanese credit card or bank account and provides English-language support. Confirm current plans and eligibility on their official sites.
Quick Comparison: Your Options at a Glance
| Option | Best for | Keeps your number? | Things to check |
|---|---|---|---|
| Cancel contract | Leaving permanently | No | Early cancellation fees, billing cycle timing |
| MNP to new carrier | Want to keep number or switch plan | Yes | MNP reservation number validity, new carrier requirements |
| Temporary suspension | Leaving short-term, plan to return | Yes | Whether your plan allows it, max suspension period, fees |
| Prepaid SIM / eSIM | Short return visits with no contract | No (new number) | Data limits, validity period, coverage |
Practical Tips Before You Leave
- Act early. Don't leave this until your last week in Japan. Some processes — especially in-store cancellations or MNP transfers — can take time.
- Screenshot or save important accounts. Many Japanese services (banking apps, government portals) use your phone number for two-factor authentication. Update these before you lose access to your number.
- Unlock your device. If your phone is SIM-locked to a Japanese carrier, request an unlock before you leave so you can use a local SIM abroad. Many carriers now unlock devices for free — check your carrier's policy.
- Keep records. Save any cancellation confirmations, MNP numbers, or suspension agreements in email or a document you can access from abroad.
Summary: Making the Right Choice for Your Situation
Deciding what to do with your leaving Japan mobile phone plan comes down to one key question: will you need your Japanese number again? If yes, port it via MNP to a flexible, low-cost plan or explore whether your carrier offers temporary suspension. If you're leaving for good, a clean cancellation — timed well to avoid extra charges — is usually the simplest route.
Whatever you decide, take the time to check your current contract terms, confirm any fees, and handle the process before your departure date rather than in a rush at the end. Your future self — whether returning to Japan or settling in a new country — will thank you for keeping things organised. You've navigated a lot to build your life in Japan; this is just one more step you can handle with confidence.