Japan eSIM: ID Checks Are for Voice, Not Data
An eSIM for Japan carries no voice line, and Article 3 of Act No. 31 (2005) ties the ID check to voice. Android needs the APN wbdata typed by hand.
13 plans for Japan, from 500 MB at $1.99 to 20 GB at $21.99, plus 6 unlimited-data tiers. 5 GB for 30 days costs $9.99 — 6th cheapest of 29 in Asia, against a $10.99 median. Our retail prices from the operator catalogue, checked 28 September 2026.
Get the eSIM
By data
Unlimited data — you pick the days
Data only: the profile carries no phone number, your own stays as it is. Not sure of the size? Work it out from your trip. Terms and refunds.
Payment and guarantees
What travellers say
What it costs per day
Cheapest per day: 3 GB for 30 days at 23¢ a day. The dearest per day is Unlimited for 5 days at $3.40. Short plans always cost more per day: validity is rounded up, and unused days are paid for anyway.
How much data to buy
Four ways people use a phone abroad, sized against this country’s own plans. The gigabytes are an estimate built from published per-hour rates — nobody measured your phone.
The hours behind each row are our assumption, not yours — put your own in and the same rates do the arithmetic.
Where a row shows a range, the cell is sized on the lower number, which assumes the evening runs on hotel Wi-Fi. On mobile data around the clock, read the upper number and take the next size up. The per-hour rates and the 15% added for background traffic are listed with their sources in the calculator.
What applies in Japan
Operator facts from the Airalo catalogue, read 28 September 2026. Rules and networks change — check the date before you rely on a line here.
Does this apply to you? (the ID check is on voice, not on data)
An eSIM Japan is Moshi Moshi, Airalo’s data-only travel profile that roams on both Softbank and KDDI at once and carries no voice line or phone number. Japan’s 2005 identity-confirmation law attaches to voice service, not to data.
Act No. 31 of 2005 requires a carrier to confirm your identity before signing a contract for mobile voice communication service. A data-only eSIM is not that service. You never sign that contract, so the identity check never reaches you. The duty sits in Article 3 of that Act (平成十七年法律第三十一号), and it attaches to 携帯音声通信役務 — mobile voice communication service (e-Gov API laws.e-gov.go.jp/api/1/lawdata/417AC1000000031, read 14 August 2026). The Moshi Moshi profile this page covers carries data and nothing else. That’s not an exemption written into the law. The law was never about this product.
Two wrong framings of this circulate online. One says Japan has no rules on SIM cards. That’s untrue — Article 3 sets a real, enforced requirement for voice lines. The other says a data SIM is “exempt” from that requirement. That’s also wrong. Exemption implies the law covers the product and then carves it out. Neither happened here. Article 2(1) defines 携帯音声通信 as wireless communication that transmits, conveys, or receives voice or other sound (音声その他の音響を送り、伝え、又は受けるもの). What Airalo sells for Japan is a data profile with no voice line and no number (Airalo catalog data, checked 14 August 2026). It isn’t the service that definition describes, so the Article 3 duty has nothing to attach to. That puts your eSIM outside the article’s scope, not inside it with a waiver attached.
This page covers you if you’re connecting a phone you already own through a Moshi Moshi eSIM for Japan, bought before departure. It doesn’t cover signing up for a voice-capable Japanese line. That contract triggers the Article 3 check whether the line arrives as an eSIM or as a plastic SIM. Such lines are sold as eSIMs too: the second organic result in our 10 August 2026 capture for japan esim tourist registration advertises a Japanese phone number with SMS. The dividing line runs between voice and data. It does not run between eSIM and SIM card. This page also doesn’t cover a Japanese resident opening a new voice contract. That reader is exactly who Article 3 was written for, and the driver’s-licence-and-address check applies to them in full.
What the 2005 Act actually says
Article 3 requires a carrier to confirm your identity before signing a contract for 携帯音声通信役務 — mobile voice communication service.
The accepted method is a driver’s licence, or another method a 総務省令 (a Ministry of Internal Affairs and Communications ordinance) sets out. For an individual, the carrier confirms name, address of residence, and date of birth (Act No. 31 of 2005, Article 3, e-Gov API, read 14 August 2026). Address of residence is the detail that stops a short-term visitor. The Act makes the carrier confirm one before the contract is signed. What counts as an address, and which documents a carrier accepts instead of a driver’s licence, sit in the 総務省令 the article points to. We haven’t read it. So we state the duty here, not the practice at the counter.
Article 2(1) supplies the definition the whole obligation rests on. 携帯音声通信 is wireless communication that transmits, conveys, or receives voice or other sound. Article 2(2) then defines 携帯音声通信役務 as a telecommunications service under the Telecommunications Business Act (昭和五十九年法律第八十六号) that relates to 携帯音声通信, drawn from services a 総務省令 sets out. Sellers in this category don’t cite either definition. We captured the 28 organic results Google returned for japan esim tourist registration on 10 August 2026. Not one title or snippet names the Act. Google’s own AI Overview answers the query with “No ID needed” — right about the outcome, silent on the reason.
The Act isn’t a recent measure. It has stood since 2005, and two amendments are in force on the text we read: 令和四年法律第六十八号, from 17 June 2022, and 令和八年法律第二十五号, from 29 May 2026. One part of the 2026 amendment is not yet in effect. The e-Gov API serves the consolidated text, so the sound-based definition in Article 2 is what stands after both. Twenty-one years and two amendments later, the tie is still to sound rather than to data.
One thing this page doesn’t claim: the exact list of services a 総務省令 assigns to 携帯音声通信役務. That ordinance carries the fine-grained list. We haven’t read it directly for this page, and no claim here depends on its content. Nor does this page rule on what you do over the data connection. An app call carries sound, and whether that touches the definition is a question for the same unread ordinance. Our claim is narrower: the contract you sign for a data profile is not a voice-service contract.
What you get: Moshi Moshi on Softbank and KDDI, 5G
Moshi Moshi is Airalo’s eSIM for Japan. It roams on both Softbank and KDDI’s 5G networks at once, data-only.
Roaming on two national carriers rather than one is unusual among Japan travel eSIMs — most sell a single-network profile. Coverage runs nationwide, including Okinawa and Hokkaido (Airalo catalog data, checked 14 August 2026). The plan’s own clock starts on first use, not at checkout.
| Data | Duration | Price |
|---|---|---|
| 500 MB | 7 days | $1.99 |
| 1 GB | 7 days | $3.99 |
| 2 GB | 15 days | $5.99 |
| 3 GB | 30 days | $6.99 |
| 5 GB | 30 days | $9.99 |
| 10 GB | 30 days | $14.99 |
| 20 GB | 30 days | $21.99 |
Airalo lists its rate separately on its site.
The plan is rechargeable, with no expiry tied to a specific package. Your checkout carries no Know Your Customer (KYC) or ID-upload step (Airalo catalog data, checked 14 August 2026). Two separate facts sit behind that. Article 3 imposes no duty on a data profile, and Airalo’s catalog lists no KYC step for this one. Neither causes the other, and a seller elsewhere is free to ask for a document the law never demanded. A top-up bought within a 180-day grace window attaches to the same profile, instead of forcing a fresh install (Airalo catalog data, checked 14 August 2026). A rented pocket WiFi router does the same job on a separate device you collect and return. An eSIM for Japan skips the extra hardware, at the cost of drawing on your phone’s own battery instead of a router’s. For a dated look at Airalo’s own track record across countries, see the Airalo review.
The APN Android makes you type: wbdata
On Android, type wbdata into the Access Point Name (APN) field manually — without it, your eSIM installs but carries no data.
iOS fills the APN automatically once the profile installs. Android doesn’t (Airalo catalog data, checked 14 August 2026). Japan sits in the 73-country slice of that catalog where Android needs the value entered by hand — 121 of 368 operator entries, 32.9%, cross-checked 3 September 2026.
The setting sits under Settings > Network & internet > SIMs > Moshi Moshi > Access Point Names on stock Android. The exact menu path shifts slightly by phone maker. Add a new APN. Set the APN field to wbdata. Leave the other fields at their defaults, save, and select it as the active APN for the Moshi Moshi line.
Do this once, before you rely on the connection — ideally at the same time as installing the profile, on Wi-Fi, before your trip starts. If a profile shows installed but produces no data on landing, check this field first — before assuming a coverage gap or an activation delay.
Before you fly: the 365-day install window
Install the profile before you leave, on a working Wi-Fi connection — not at the airport.
The QR code or install link needs internet to complete, and an airport connection isn’t guaranteed. The profile stays installable for 365 days from purchase, so buying weeks or months ahead of your trip costs nothing (Airalo catalog data, checked 14 August 2026).
Confirm the profile shows as installed in your phone’s settings before you board. Set the Android APN to wbdata at the same time — doing both steps together saves you a second trip into the settings menu after landing. Nothing needs to be active yet. Moshi Moshi activates on first use, once your phone actually connects to Softbank or KDDI, not at the moment of installation. A profile that shows installed but inactive at the gate is expected, not a fault.
If this is your first eSIM install, the steps are the same regardless of destination. The iPhone install guide and the Android install guide cover the QR-scan and manual-entry paths in full.
On landing: dual SIM, no Japanese number
A Moshi Moshi profile carries data only. It has no Japanese phone number, no SMS, and no calling minutes. Switch data roaming on for the Japan eSIM specifically once you land. The connection completes once your phone reaches a Softbank or KDDI tower.
Running it alongside a home SIM works on any dual-SIM phone. Set Moshi Moshi as your data line. Turn off cellular data — not the whole line — on your home SIM, so nothing pulls data over an expensive home-carrier roaming connection by accident. Calls and texts on your home line still run at that carrier’s own roaming rates. That’s a separate cost, unrelated to Moshi Moshi or to Act No. 31.
If the home SIM carries its own international roaming plan, turn that plan’s data roaming off too, not just its notifications. Two active data connections on one phone can conflict, and the home plan is the expensive one to lose track of.
If an eSIM isn’t working after landing, check the Android APN from the section above before assuming a network problem. Give your phone a minute on a Softbank or KDDI tower. Confirm the APN field reads wbdata. Only then treat it as a fault.
Anything that verifies you by SMS to a Japanese number sits outside what a data-only profile does — a delivery app tied to a Japanese number, a Japanese bank’s one-time password, a loyalty sign-up that texts a code. Those needs rarely come up on a short trip on a phone you already own. If one does come up, you need a voice-capable Japanese line — the product Article 3’s identity check governs, not this one.
Coverage: Tokyo, Osaka, Kyoto, the shinkansen
Moshi Moshi roams on Softbank and KDDI’s 5G networks nationwide, including Okinawa and Hokkaido (Airalo catalog data, checked 14 August 2026). Tokyo, Osaka and Kyoto sit on those two networks the same way a Japanese subscriber’s phone does — a roaming profile connects to the host carrier’s own towers.
Naha and Sapporo fall under that same nationwide statement, not a separate regional one (Airalo catalog data, checked 14 August 2026).
5G speed depends on your phone’s own band support, and on Softbank’s and KDDI’s live network state on a given day. A 5G-capable phone isn’t guaranteed a 5G signal everywhere the two networks reach. 4G is the fallback where it doesn’t. On the shinkansen we have no dated, route-specific signal report. We don’t publish a coverage claim we haven’t got. What is known is the shape of the risk: a long mountain tunnel is where a signal drops, on any carrier. Treat a tunnel-heavy route, or a rural itinerary beyond the three cities named here, as unverified. Check Softbank’s or KDDI’s own coverage map before you rely on it there.
FAQ
Is it worth getting an eSIM for Japan?
Which eSIM is best for Japan?
Does Japan's 2005 identity-confirmation law apply to a travel eSIM?
Do I need a Japanese address to buy a data eSIM?
Why does a Japanese carrier ask for ID when my data eSIM didn't?
What's the APN for Moshi Moshi on Android?
How do I register a Moshi Moshi eSIM for Japan?
Does Moshi Moshi work on the shinkansen?
Sources and freshness
*Checked against Act No. 31 of 2005 (平成十七年法律第三十一号), retrieved via the e-Gov API (laws.e-gov.go.jp/api/1/lawdata/417AC1000000031), and against Airalo’s Japan catalog data: 14 August 2026.
Two amendments are in force. 令和四年法律第六十八号 took effect 17 June 2022. 令和八年法律第二十五号 took effect 29 May 2026, with one part not yet in force. Neither changes the voice/data boundary quoted above. We haven’t read the 総務省令 that lists the specific services falling under 携帯音声通信役務 directly, and no claim on this page depends on its exact content. Act No. 31 can be amended again without this page updating automatically — recheck the e-Gov text directly if it’s been more than a few months since this date.*
Sources cited only — expert review pending. For individualized advice, consult a licensed professional.