Japan eSIM with Phone Number: Who Needs One and What Happens After You Land

This page contains affiliate links. If you order from Sakura Mobile through these links, I may earn a commission.

This guide is for trips to Japan of 1 to 90 days. You will need a Japanese phone number less often than you think. In this guide I use Sakura Mobile’s Travel Voice + Data eSIM (Prepaid Voice + Data eSIM) as the example, split travelers into those who need a Japan eSIM with a phone number and those who don’t, and walk the first group through what happens after landing.

Who needs a Japanese number, and who doesn’t

Photo: MaedaAkihiko / Wikimedia Commons (CC BY-SA 4.0, resized)

Write out your plan. If even one of these three is on it, you need a Japanese phone number.

• A booking asks for a number: a restaurant or taxi booking asks for a Japanese phone number or an SMS code
• A Japanese app wants SMS verification: the app sends a code by SMS when you sign up
• You want to call: your hotel, a guide, or an emergency contact, from a Japanese number

If all you use is maps, translation and messaging apps like LINE or WhatsApp, you don’t need a number. Sakura Mobile’s data-only eSIM arrives by email, and there is no in-person ID check to stop for after you land. It really comes down to these two.

My rule: the moment a booking form asks for a Japanese phone number, I go with the number. If you plan to book a restaurant before you fly, open that booking page now and check the form.

What the eSIM with a phone number gives you: 3GB a day and capped call minutes

Photo: Leo Okuyama / Unsplash (Unsplash License)

The Travel Voice + Data eSIM runs on au’s 5G network and comes with a Japanese phone number. Data, calls and SMS sit on one eSIM, and plans run from 1 to 90 days.

Data: high speed up to 3GB a day, and it doesn’t cut off

You get up to 3GB of high-speed data per day. According to the official note, going over 3GB in a day does not disconnect you; speed drops to 200 Kbps for the rest of that day. If you stream a lot of video, watch it on WiFi and save the day’s 3GB for maps and search.

Calls: domestic minutes are capped by plan length

The cap on domestic calls depends on how many days you choose. The right-hand column is the cap divided by the longest number of days in that band (my own arithmetic).

Minutes beyond the cap are charged separately; the amounts are on the official “Calls and SMS rates” page.

SMS: Sakura lists Japanese app verification as a use

You can send and receive domestic SMS. The uses Sakura Mobile lists are restaurant and taxi bookings, Japanese app verification, and contacting your hotel, guide or emergency contacts.

After you land: it won’t work until your ID is checked

Photo: Nanashinodensyaku / Wikimedia Commons (CC BY-SA 4.0, resized)

Under Japanese law, the Travel Voice + Data eSIM needs an ID check before the service starts; Sakura Mobile does it in person. You can do it at selected airport counters and at the Shinjuku office. Sakura Mobile’s data-only eSIM arrives by email; this one is collected in person.

After immigration and baggage claim, you have one more stop. Build that time in before you head to your hotel. Until the ID check is done, this eSIM gives you no connection. Screenshot the route to the counter and your hotel address before you fly, so you are less likely to get stuck on arrival.

If you do the ID check at the Shinjuku office, plan to get from the airport to Shinjuku without this eSIM, and work out the route before you leave home.

Three checks before you book: phone, payment, price

Photo: Sinafe / Wikimedia Commons (CC BY-SA 4.0, resized)

Phone: it must be unlocked

The phone you put the eSIM on must be unlocked (not tied to a carrier). If you bought it from your carrier, ask them whether it is unlocked before you fly. Sakura Mobile lists iPhones sold in mainland China, Hong Kong and Macau as not compatible (see the FAQ below).

Payment: Japanese yen only

You pay in Japanese yen only. If the official page shows another currency, treat it as a guide; what you actually pay depends on the exchange rate and your card issuer.

Price: total for 7 days (e.g. Nov 10–16, 2026), ¥10,340 (tax incl.)

For 7 days (I picked November 10–16, 2026) the total is ¥10,340 (tax incl.). It is not a daily rate; the total rises with the number of days. As a rough guide for a short stay, 1 day alone totals ¥6,160 (tax incl.). The official price table works by picking your usage dates, so the price changes with the number of days you choose. This is the yen-denominated price as of November 3, 2026. I could not find any pickup or ID-check fee on the official page (as of November 3, 2026). Check the final amount on the screen before you pay.

Which one fits your trip

Photo: Simo Räsänen (Ximonic) / Wikimedia Commons (CC BY-SA 4.0, resized)

If you go with a number, two things are left before you fly: confirm your phone is unlocked, and pick your dates on the official page. After that, it is one stop when you land, at a selected airport counter or the Shinjuku office.

Japan eSIM with phone number: FAQ

Photo: Yoh-Plus / Wikimedia Commons (CC BY 4.0, resized)