It's the question we're asked most before departure: “without a Japanese number, how do I make calls once I'm there?” Honest answer: you probably won't make a single “old-fashioned” call during your stay — and you won't notice the difference. Here's how it all works, and the three settings to sort out before take-off.
Calling with a data eSIM: everything goes through your apps
The PlanJapan eSIM provides an internet connection on the NTT docomo 4G/5G network. And your calls and messages already go through the internet every day: WhatsApp, iMessage, FaceTime and Messenger use data, not the traditional phone line. Once connected in Japan, you call, write and video chat exactly as you do at home — TikTok, Instagram, Google Maps, YouTube, WhatsApp… all available without restriction.
An eSIM with no number? Yes — and your number stays yours
A data eSIM doesn't include a Japanese phone number, and you don't need one to travel. Your phone runs as a dual SIM: your usual SIM card stays in place with your home number, and the PlanJapan eSIM is added alongside it to provide the data. Friends and family reach you on your usual number, and you keep receiving your texts — including bank codes.
| You want to… | How | Which line |
|---|---|---|
| Make a call or a video call | WhatsApp, FaceTime, Messenger | PlanJapan eSIM (data) |
| Send messages and photos | iMessage, WhatsApp, Instagram | PlanJapan eSIM (data) |
| Receive a text (bank code) | Standard text reception | Your home SIM, still active |
| Calls/texts from a Japanese number | Not included — the eSIM is data only | — |
Nothing to do on your sideYour WhatsApp number, your contacts and your conversations are kept automatically. The eSIM only handles data. Do I keep my number? →
The 3 settings to sort out before take-off
Open Settings → Mobile Data → your usual line and turn off “Data Roaming” (iPhone) or data roaming (Android). This is THE setting that prevents bill shock: your home carrier can no longer charge you a single byte.
Choose the PlanJapan line as your data line, with its data roaming switched on: all your data then runs on the NTT docomo network. The installation guide shows every screen →
Once its data is off it uses nothing, but it keeps receiving your texts. Receiving a text is usually free abroad — check with your carrier; answering an incoming call, on the other hand, may be charged.
In real life: three everyday situations
Find the address on Google Maps, compare reviews and let the directions take you to the door. Many places can be booked online straight from their listing — all through your eSIM's data.
From your hotel room or even the Shinkansen, start a FaceTime or WhatsApp video call over data. For your family nothing changes: they call you on your usual number, as always.
The confirmation code arrives by text on your home line, still active as a dual SIM. And your banking apps work without a VPN — nothing is blocked.
Now you know: an eSIM without a number takes nothing away from you — above all it saves you from roaming charges. All that's left is to choose your Japan eSIM plan — unlimited from 10 to 30 days or 10/20/50 GB, QR code by email in 2 minutes. More questions? See our FAQ.
