Mobile in Japan: which SIM or plan to choose for your situation

Mobile in Japan has a reputation for being expensive and complicated — a reputation that was fairly accurate ten years ago but no longer reflects reality. The market has changed significantly since the government pushed the major carriers to lower prices in 2021, and today there are reasonable options for both visitors and residents. The problem is that the options are many and not all are equally suitable depending on your situation.

When I arrived in Japan, over fifteen years ago, things were radically different. Japanese phones didn’t work with foreign SIMs, and foreign phones weren’t compatible with the Japanese network. My first phone here was a ガラ携帯 (garakei) — the term used for Japanese mobiles of that era, technologically impressive for their time but completely cut off from the rest of the world. That’s all ancient history now.

This guide is organised in two blocks: visitors first, then residents. If you already live in Japan, skip straight to the second part.

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For visitors: travel SIMs and eSIMs

The simplest option for a short trip is no longer buying a SIM at the airport — though that’s still possible — but activating an eSIM before you leave home. You arrive at Narita or Haneda with mobile coverage from the moment you land.

IIJmio Tourist eSIM: one of the best options for visitors. Plans from 15 days (3 GB) to 30 days (10 GB or 15 GB). Data only, no local calls. Reasonable price and IIJ coverage (Docomo network). Activated through the app before you arrive.

Docomo Tourist eSIM: Japan’s main carrier offers 15 or 30-day plans directly. More expensive than IIJmio but with the most extensive coverage in the country, useful if you’re going to rural or mountain areas.

Airalo / Holafly / others: international platforms that resell Japanese network eSIMs. Convenient for comparing prices, though it’s worth reading the fine print about whether hotspot use (sharing data with other devices) is allowed.

Physical SIM cards at the airport: still available. IIJmio, SoftBank and others have booths at Narita and Haneda with options from ¥3,000-5,000 for 7-30 days. Useful if your phone doesn’t support eSIM or if you’d rather not configure anything before travelling.

One general warning: tourist SIMs in Japan are data-only — they don’t include a local phone number for calls or SMS. For apps like WhatsApp or internet calls (Skype, FaceTime, LINE) you don’t need a local number. But if you need a Japanese number — to register for certain services or receive verification SMS — you’ll need another solution.

How many GB do you need?

For normal tourist use (Google Maps, social media, messaging, some wifi streaming), 5-8 GB per week is a reasonable estimate. If you use your phone a lot as a hotspot or watch a lot of video on data, double that figure.

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For residents: the MVNO and sub-brand market

If you live in Japan with a residence card, the landscape is different. You have access to the full market, including the cheapest plans, and can set up direct debit from your Japanese bank account.

The market divides into three tiers:

The big three (Docomo, SoftBank, AU): full plans with maximum coverage, in-store customer support and all features. Also the most expensive: ¥7,000-10,000 per month for a plan with unlimited calls and enough data. Increasingly hard to justify when the alternatives are this good.

Sub-brands of the big three: ahamo (Docomo), linemo (SoftBank), povo (AU). 100% online plans with no in-store support, significantly lower prices. Coverage is identical to the parent carrier because they use the same network.

MVNOs (virtual network operators): IIJmio, Rakuten Mobile and many others. The cheapest on the market, especially for low-data plans.

The most popular options for residents

Ahamo (Docomo): ¥2,970/month for 20 GB with 5-minute calls included. One of the best value-for-money options in the market for moderate-to-heavy data users. Docomo coverage is the most extensive in Japan. Requires fully online management.

Linemo (SoftBank): two options — 3 GB plan for ¥990/month (very affordable for light users) and 20 GB plan for ¥2,728/month. The 3 GB plan is the cheapest in the market for moderate use.

Povo (AU): unusual model — the base plan is free (0 yen/month) and you add data packages as needed. Useful as a second SIM or for people with very irregular usage. If you don’t top up anything for 180 days, the plan is cancelled.

Rakuten Mobile: Rakuten’s coverage has improved significantly in recent years, though it’s still below Docomo in rural areas. Their prices are tiered: ¥1,078/month up to 3 GB, ¥2,178/month up to 20 GB, ¥3,278/month unlimited. For heavy users, the unlimited plan is competitive.

IIJmio: Japan’s most established virtual operator. Plans start at ¥858/month for 2 GB. Cheaper than the big carriers’ sub-brands, with a good service reputation. Uses the Docomo or AU network depending on the plan you choose.

Which one to choose?

If you use 10-20 GB per month and want simplicity: ahamo. Pay once, good coverage, no surprises.

If you use less than 5 GB per month: linemo 3 GB (¥990) or IIJmio are the cheapest options.

If you travel frequently outside cities or go to rural areas often: ahamo or Docomo directly, for the best coverage.

If you want the convenience of being able to visit a physical store: the big three, though the price difference from ahamo is hard to justify for most people.

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Number portability and switching carriers (MNP)

If you already have a Japanese number and want to switch carrier while keeping it, the process is called MNP (Mobile Number Portability). In Japan it’s relatively straightforward:

1. Request the MNP code from your current carrier (usually through the app or website)
2. Sign up with the new plan using that code
3. The number transfers automatically in 1-2 days

Online carriers like ahamo and IIJmio have a fully digitised process. The MNP code is valid for 15 days.

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FAQ

Can I use my home SIM in Japan with roaming? Yes, most carriers from Europe and North America have roaming in Japan. The cost is significant (and data is often limited). For a short visit it may be enough; for more than a week or if you’ll be using a lot of data, a local SIM is more practical.

Do I need a Japanese phone to sign up for a plan? No. Any unlocked phone compatible with Japanese frequencies (most current smartphones are) works. Online carriers don’t require you to buy a handset from them.

Can I sign up for ahamo without knowing Japanese? The ahamo website has an English option. The sign-up process is online and relatively straightforward. Customer support is in Japanese.

What happens if I leave Japan and no longer need the plan? You can cancel the contract with advance notice (generally one month or less, with no cancellation fee for most MVNOs and sub-brands). The major carriers may charge an early termination fee if you’re on a contract with a commitment period.

As a foreign resident, do I need anything special to sign up? Your residence card (在留カード), a Japanese bank account for direct debit, and in some cases your My Number. The process varies by carrier. The My Number guide covers what the card is used for and how to get it.

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Prices updated June 2026. Japan’s telecoms market changes frequently — check current rates on each carrier’s website before signing up.