Japan eSIM With a Phone Number vs Data-Only: Which?

Most visitors to Japan do not need a Japanese phone number, and a data-only eSIM is enough. A data-only eSIM gives you maps, messaging apps, translation and internet calls, but it has no Japanese number and cannot receive SMS. You only need a voice-and-SMS plan if something in Japan has to text or ring a Japanese number that belongs to you.

This guide sets out exactly what data-only plans cannot do, the situations where a real number matters, and what each option costs, based on the providers’ and platform makers’ own pages.

What is the difference between a data-only eSIM and a voice eSIM?

A data-only eSIM sells you mobile data and nothing else. It is not attached to a phone number, so nobody can call or text it. Ubigi states it plainly on its help centre: “You will not get a new mobile phone number with your Ubigi eSIM. Ubigi provides mobile data connectivity only and does not provide any mobile phone number to make standard phone calls or text messages.”

Airalo describes the same limitation for its data-only packs and points travellers to a dual-SIM workaround instead: keep your home line active for voice and SMS, and use the eSIM only for data.

Japan-specific travel eSIMs follow the same pattern. Sakura Mobile’s Travel eSIM product page describes the product as “No phone number, data only”, running on 5G au for its unlimited option and 5G docomo for its 3GB/day option.

A voice eSIM is a Japanese mobile subscription. It issues you a real 070, 080 or 090 number that rings, receives SMS, and can be typed into Japanese forms. Mobal, which sells to visitors as well as residents, describes its numbers as “Real Japanese phone number” in the 070/080/090 range.

What can a data-only eSIM in Japan not do?

Four things, and they are worth reading carefully before you decide.

It has no Japanese number to give out. There is nothing to write on a form, tell a restaurant, or hand to a courier. If a Japanese business needs a callback number, you have only your home number, which is an international number to them.

It cannot receive SMS at all. Not from Japanese senders, not from your bank at home, not from a two-factor code. The network line simply has no messaging service attached. This is the limitation that catches people out, because SMS verification is common in Japanese apps and booking flows.

It cannot dial Japanese landlines or emergency-style service numbers. Many hotels, clinics, restaurants and rental desks list only a landline. Internet calling apps do not reach those numbers unless you pay for a service that bridges to the public phone network.

It cannot receive calls. If a restaurant wants to confirm a booking, or a lost-property office wants to reach you, there is no line for them to ring.

None of this makes data-only a bad choice. For a traveller who books online, navigates with maps, and messages family through apps, none of the four limitations ever comes up.

When do you actually need a Japanese phone number?

These are the situations where a data-only plan genuinely blocks you.

SMS verification on Japanese services. Some Japanese apps, delivery services and account signups verify you by texting a code. A data-only eSIM cannot receive that code. Your home number often can, if you leave your home line switched on with roaming for SMS, but this depends entirely on your home carrier’s roaming terms and charges.

Restaurant and clinic callbacks. Popular restaurants that take reservations by phone, and medical clinics, frequently ask for a contactable local number and may call to confirm or to tell you a table has opened.

Deliveries and couriers. If you have anything shipped to a hotel or a locker, or you use a luggage-forwarding service, the driver’s first move when something goes wrong is to phone the number on the label.

Forms that reject international numbers. Some rental agreements, short-stay accommodation registrations and service signups have a phone field that only accepts a Japanese-format number. There is no workaround for a form that rejects your country code.

Long stays and anything resembling residency. If you are moving to Japan rather than visiting, a Japanese number is effectively a prerequisite for daily life. Sakura Mobile notes that its numbers are “normal Japanese phone numbers (070, 080, 090)” that work for purposes such as banking and apartment rental.

Japan eSIM comparison: data-only vs voice+SMS vs keeping your home line

All prices below are taken from the providers’ own pages and are current as of September 2026. Prices change, and some are quoted before tax on the source page, so check the provider’s page before buying.

How much does a Japanese eSIM with a phone number cost?

Three providers publish English pricing, and they target different lengths of stay. All figures below are as of September 2026, taken from the pages linked at the end of this article.

Two things stand out. First, a Japanese number is cheap on its own but the setup fees are not trivial: Mobal’s ¥4,950 upfront eSIM cost and Sakura Mobile’s ¥5,500 activation fee, both as of September 2026, are one-off charges that dominate the cost of a short trip. Second, IIJmio’s SMS-capable data SIM is a middle option worth knowing about, though its visitor page frames these plans as being for people living in Japan.

Note also that the providers’ rates are not directly comparable: as of September 2026 Mobal quotes ¥44 per minute for domestic outgoing calls while Sakura Mobile quotes 16.5 yen per 30 seconds, which works out to ¥33 per minute. Sakura Mobile is cheaper per minute on the published figures, but Mobal’s plans have no minimum duration and its voice-only tier is a good deal less per month.

Why is buying a Japanese voice line harder than buying data?

Because Japanese law treats voice lines differently. Japan’s Ministry of Internal Affairs and Communications administers the Mobile Phone Unauthorized Use Prevention Act, which requires mobile voice communication carriers to verify a subscriber’s identity when a contract is signed and when a line is transferred, and which extends to SIM cards.

That is why a data-only travel eSIM is a two-minute checkout with a card, while a voice line asks for a passport or residence card. Mobal requires customers to be 18 or over and to provide a valid current passport. Sakura Mobile routes residents through an online ID check using a residence card or My Number Card, and visitors through passport verification at pickup. IIJmio states that identification documents “such as your residence card and driver’s license, are required for identity verification” on its voice SIM.

The practical consequence: you cannot decide you need a Japanese number at 9pm on your second night and have one working by 10pm. If you think you will need one, arrange it before you travel or on arrival, not mid-trip.

Can you keep your home number and still use a Japan data eSIM?

Yes, and for most travellers this is the sensible setup. Modern phones run two lines at once, so your home number stays reachable for SMS and calls while the Japanese eSIM carries all your data.

On iPhone, Apple documents that you can label each plan, choose which number is used for calls and messages by default, and pick which line uses cellular data. Apple notes that “One number at a time can use cellular data”, and that with Allow Cellular Data Switching turned on, “while you’re on a voice call on your voice-only number, that number automatically switches to use voice and data.”

On Android, Google’s Pixel documentation describes the same structure: you “choose which SIM your phone uses for data, calls, text messages, and more”, but “Only one SIM can be the default for data.” Google also notes that on Pixel 7 and later you can run two eSIM profiles at once, subject to carrier support.

The setting people most often get wrong is data roaming. Airalo’s guidance is to set your primary line as the default voice line while the eSIM is selected for mobile data, and it warns that this “may incur roaming charges, so we highly encourage you to consult your home provider to learn about the charges before proceeding.”

A useful middle path: turn cellular data off for your home line, leave the line itself enabled so SMS and calls still arrive, and set the Japanese eSIM as your data line. You stay reachable on the number your bank and your family already have, without paying international data rates. Confirm the specifics with your own carrier, since roaming terms differ.

Which should you choose?

Work through this in order.

• Trip under a month, bookings made online, family reachable by app: a data-only eSIM is enough. Keep your home line on for SMS if your carrier allows it cheaply.
• You expect phone reservations, deliveries, or Japanese app signups: a Japanese voice line pays for itself in avoided friction. Mobal’s voice-only tier plus a cheap data eSIM is often less than a bundled voice+data plan.
• Staying several months, or moving: get a full Japanese voice+data plan from a provider like Sakura Mobile or IIJmio, and expect an ID check.
• You cannot receive SMS on your home line abroad: this is the one case where the decision flips. If your home carrier will not deliver SMS to you in Japan and you need verification codes, a Japanese number stops being optional.

FAQ

Does a data-only eSIM for Japan come with any phone number at all?
No. Ubigi’s help centre states directly that its eSIM does not provide a mobile phone number, and Sakura Mobile’s Travel eSIM is described as “No phone number, data only”. Airalo describes the same limitation for its data-only packs.

Can I receive a Japanese SMS verification code on a data-only eSIM?
No. There is no messaging service on the line. If you need to receive SMS in Japan, you need either a Japanese voice or SMS-capable line, or your home line kept active with roaming enabled.

Can I make phone calls using a data-only eSIM?
You can make internet calls through apps over the data connection. What you cannot do is dial a Japanese landline or mobile number through the phone network, or be called on a Japanese number, because there is no such number attached to the line.

Can a tourist get a Japanese phone number without a residence card?
Some providers sell to visitors. Mobal’s published requirements are that you are 18 or over and provide a valid current passport, and Sakura Mobile offers passport verification at pickup locations for people without a Japanese address. Requirements and availability change, so confirm with the provider before you rely on it.

Is it cheaper to add a Japanese number or to use my home line for SMS?
It depends entirely on your home carrier. If your carrier delivers incoming SMS abroad at no charge, keeping your home line on is usually cheaper than paying setup fees of ¥4,950 or ¥5,500 for a short trip. If it charges per message or per day, the arithmetic can go the other way. Check your carrier’s roaming terms and compare against the figures above, which are as of September 2026.

Sources

• Japan eSIM: eSIM with Japanese Phone Number — Mobal (accessed 2026-09-01)
• Japan SIM Card – Data & Phone Number Plans — Mobal (accessed 2026-09-01)
• Travel eSIM for Japan — Sakura Mobile (accessed 2026-09-01)
• Voice SIM & eSIM Plans with Japanese Phone Number — Sakura Mobile (accessed 2026-09-01)
• VOICE SIM and DATA SIM available in Japan — IIJmio (accessed 2026-09-01)
• What will be my Ubigi eSIM mobile phone number? — Ubigi Help Center (accessed 2026-09-01)
• How can I receive SMS and calls while connected with my data-only eSIM? — Airalo Help Center (accessed 2026-09-01)
• Using Dual SIM with an eSIM — Apple Support (accessed 2026-09-01)
• How to use dual SIMs on your Google Pixel phone — Google Pixel Phone Help (accessed 2026-09-01)
• Prevention of criminal use of mobile phones — Ministry of Internal Affairs and Communications, Japan (accessed 2026-09-01)