One of the quieter worries that comes with a visa change in Japan is this: will I lose my mobile number? If you are switching from a student visa to a work visa, moving onto a spouse visa, or upgrading to permanent residency, mobile number portability during a visa change in Japan is something you need to think about before you visit the carrier shop — not after. The good news is that in most cases you can keep your number, but there are a few important things to check first.
Does Your Visa Status Affect Your Mobile Contract?
Your mobile phone contract in Japan is tied to your residence card (zairyu card), not directly to your visa category. However, your residence card shows your visa status and its expiry date, and carriers use this information when you sign up or when you update your details. A change in visa status means your residence card will be reissued with a new status and, usually, a new period of stay. This updated card is what matters to your carrier.
The key concern is this: if your contract was set up under your old visa status, you are generally required to notify your carrier when your status changes and to show your new residence card. Failing to do so can — in some cases — lead to a contract being flagged or not renewed. Proactively updating your details keeps everything running smoothly.
Can You Keep Your Number? Understanding Mobile Number Portability (MNP)
Japan has a Mobile Number Portability (MNP) system, which means you can take your phone number with you even if you switch carriers. A visa change does not cancel this right. Whether you stay with the same carrier or move to a new one, your number can travel with you — as long as your contract remains active at the time of the transfer.
Here is what could go wrong: if your contract is cancelled (for example, because you failed to renew it or your payment method lapsed), you may lose the number before you have a chance to port it. So the priority is always to keep your contract active during any transition period.
Step-by-Step: What to Do When Your Visa Status Changes
Step 1 — Get Your New Residence Card First
Before you do anything with your mobile carrier, visit the immigration office and complete your visa status change. Once approved, you will receive a new residence card showing your updated status and new expiry date. This card is the document your carrier needs.
Step 2 — Notify Your Carrier as Soon as Possible
Visit your carrier's shop or log in to your online account and update your registered information with your new residence card details. Most major carriers and MVNOs (smaller virtual operators) require this. Bring:
- Your new residence card
- Your current SIM card or phone
- Your registered email address or account PIN (if updating online or by phone)
If your carrier requires a Japanese credit card and your card details have changed (for example, you got a new card after starting work), update your payment information at the same time.
Step 3 — Check Your Contract Conditions
Some contracts have minimum periods or early cancellation fees. If you are thinking of switching carriers at the same time as your visa change, check whether you are still inside a lock-in period. Switching too early could mean a cancellation fee. Confirm the current terms directly on your carrier's official website, as these conditions change regularly.
Step 4 — If You Need to Switch Carriers, Use MNP
If your current carrier is no longer a good fit — for example, your payment situation has changed or you want better support in English — you can port your number to a new carrier using MNP. The process looks like this:
- Request an MNP transfer number (MNP yoyaku bangou) from your current carrier. This is a temporary code, valid for a limited number of days (confirm the exact validity period with your carrier).
- Sign up with your new carrier, providing this transfer number along with your new residence card and other required documents.
- Your new SIM will activate and your old contract will close automatically.
Do not cancel your old contract before completing the port — you will lose your number if you do.
Foreigner-Friendly Carriers Worth Knowing
If your visa change means you are now setting up a brand-new contract (for example, you previously used a prepaid SIM as a student), or if you want a carrier that is easier to deal with in English, here are some options that are known to be accessible for foreign residents:
| Carrier / MVNO | Japanese credit card required? | English support? | Notes |
|---|---|---|---|
| GTN Mobile | No | Yes (multilingual) | Accepts residence card; flexible payment options; good for newcomers |
| Mobal | No | Yes (English) | No Japanese bank account needed; suited to those still setting up finances |
| docomo / au / SoftBank | Usually yes | Limited | Wide coverage; easier once you have a Japanese credit card and bank account |
Plans, prices and requirements change frequently. Always confirm the latest details on each carrier's official website before signing up.
Common Situations and Quick Answers
Student Visa → Work Visa
This is one of the most common transitions. If you already have a contract SIM, update your residence card details with your carrier after your new card is issued. Your number is safe. If you were on a prepaid SIM and now want a full contract (often better value for long-term residents), apply fresh with your new residence card and use MNP to bring your number across.
Work Visa → Permanent Residency or Long-Term Resident Visa
Your contract should continue without issues. Update your residence card information with your carrier as usual. Permanent residency can actually make it easier to meet carrier requirements going forward.
Spouse / Dependent Visa
The same rules apply. Show your new residence card to your carrier. If you are joining a family plan held by your spouse, check whether the primary account holder needs to make any updates on their end.
Summary: Keep Your Number Safe During Any Visa Change
Changing your visa status in Japan does not mean losing your mobile number. Mobile number portability gives you the freedom to keep your number whether you stay with the same carrier or move to a new one. The most important steps are simple: get your new residence card first, notify your carrier promptly, keep your contract active and payments up to date, and use the MNP process if you decide to switch. If you are still building up your life in Japan — no Japanese credit card yet, no bank account — foreigner-friendly options like GTN Mobile or Mobal can bridge the gap while you get settled.
A visa change is a big milestone. With a little preparation, your phone number can make the journey with you.