Telstra roaming in Japan: use it or get an eSIM?
Key facts
- Telstra roaming in Japan is billed per day or bundled by plan, so check your exact rate in the My Telstra app; we do not quote carrier prices.
- A VoaSim eSIM for Japan costs USD 18.90 for 5 days, USD 30.90 for 10 days and USD 61.90 for 30 days, with truly unlimited data and no throttling.
- The eSIM connects automatically to NTT Docomo, SoftBank and KDDI au on 4G and, where available, 5G, including subways and Shinkansen routes.
- Your Telstra number stays active for calls and SMS; just turn off data roaming on that line to avoid surprise charges.
- Validity starts at the first connection in Japan, so install the QR code at home and keep the eSIM line off until you land.
See the exact price for your dates
Japan is one of the easiest countries in the world to stay connected in. The networks are excellent, and you will have signal in the subway and on the Shinkansen. The only question is how you pay for it.
If you are on Telstra, you have two sensible options: switch on Telstra's international roaming before you leave Australia, or install a travel eSIM and keep your Telstra line for calls and SMS only. Here is a fair look at both, with exact eSIM prices.
How Telstra roaming works in Japan
Telstra sells international roaming as a day pass or as an inclusion bundled into some plans. In practice that means you pay per day of use, you get a daily data allowance, and speeds are usually reduced once that allowance is gone. Roaming generally has to be enabled on your service before you travel, and rates and inclusions change by country and by plan.
Because of that, we will not quote a price here. Open the My Telstra app or telstra.com.au, check what Japan costs on your exact plan, and check how many days of your trip would be billed. That is the only number that matters.
When is Telstra roaming the better pick? If your employer pays the bill, if you need your Australian number to receive calls and bank SMS codes while abroad, or if the trip is short and your plan already includes roaming days you are not using. It is one line on your existing bill and there is nothing to install.
What a VoaSim eSIM costs for Japan
VoaSim charges one price per duration, the same for every destination. The Japan price is the Europe price is the Brazil price. Today's rates already include the 15% promo:
| Plan | Price | Per day |
|---|---|---|
| 5 days | USD 18.90 | USD 3.78 |
| 7 days | USD 23.90 | USD 3.41 |
| 10 days | USD 30.90 | USD 3.09 |
| 15 days | USD 42.90 | USD 2.86 |
| 30 days | USD 61.90 | USD 2.06 |
| 60 days | USD 106.90 | USD 1.78 |
Data is truly unlimited: no cap, no speed throttling, no hidden fair-use clause. Trips of 1 to 4 days pay the 5-day package, and the maximum is 90 days per eSIM. A second eSIM in the same order gets 10% extra off, which is handy for a couple. Payment is by international credit or debit card in USD through Stripe, with an invoice by email. Run your dates in the simulator to see the exact figure.
Telstra roaming vs VoaSim eSIM: side by side
| Telstra roaming | VoaSim eSIM | |
|---|---|---|
| Cost model | Per day of use or bundled in your plan | Fixed price per duration, paid once |
| Data | Daily allowance, usually slower after it | Unlimited, no throttling |
| Your Australian number | Stays fully active for calls and SMS | Stays on the phone; keep it on Wi-Fi or data off |
| Setup | Enable roaming before you fly | Scan a QR code before you fly |
| Billing | Appears on your next Telstra bill | Paid upfront in USD, invoice by email |
| If it fails | Telstra support | Human support plus 100% refund if it cannot connect |
Many travellers do both: eSIM for all data, Telstra kept alive for incoming calls and one-time codes. See more roaming comparisons or our plan picks.
Today's prices
Today's promo prices (15% off), the same for every destination. Second eSIM in the same order: 10% extra off. Trips of 1-4 days use the 5-day package.
Coverage in Japan: Docomo, SoftBank and KDDI au
The VoaSim eSIM connects automatically to local Japanese networks, including NTT Docomo, SoftBank and KDDI au, on 4G and, where available, 5G. You do not pick a network manually; the phone selects the strongest signal.
Japan's coverage is among the best anywhere. You keep signal in Tokyo and Osaka subway tunnels, along the Shinkansen line, and in Kyoto's temple districts. Hiroshima, Sapporo and the smaller towns on the way are well served too. Rural mountain areas and some ferry routes can drop out, which is normal for any network, Telstra roaming included.
Useful in practice: Google Maps and the train apps work over data, so you can route yourself through Shinjuku station without pre-downloading anything. WhatsApp and app calls work over data as well. What the eSIM does not give you is a Japanese phone number or traditional voice calls, so if a hotel or restaurant needs to ring you, give them your Telstra number.
How to avoid accidental roaming charges
The most common Japan bill shock is not the eSIM. It is a phone that quietly used Telstra roaming for two days before anyone noticed. Do this:
- Install the VoaSim eSIM at home, from the QR code emailed to you within minutes of purchase.
- Leave the eSIM line switched off until you land. Validity starts at the first connection to a network at the destination, and on Android you should not switch on the eSIM's data before the trip.
- In your phone settings, turn off data roaming on the Telstra line. Keep the line itself active if you still want calls and SMS.
- On landing, switch the eSIM line on and set it as the mobile data line. Wait a minute for it to register on a Japanese network.
- Check that your Telstra line still shows data roaming off after the phone reconnects.
If nothing connects, the free eSIM Rescue tool diagnoses an eSIM of any brand with no signal, and support is human. If we still cannot get it working, you get a 100% refund.
Will your phone work?
You need an eSIM-capable, carrier-unlocked phone. That covers iPhone XR or newer, Samsung Galaxy S20 or newer, Google Pixel 3 or newer, and most handsets released from 2020 on.
Quick universal check: dial *#06#. If an EID number appears alongside the IMEI, your phone supports eSIM. If your handset was bought on a Telstra contract and is still locked, ask Telstra to unlock it before you travel; VoaSim does not sell physical SIM cards.
Two more notes. Hotspot and tethering depend on the plan, so do not build your trip around it, ask support first. And if Japan is part of a longer trip, remember the eSIM covers 170 destinations at the same price per duration, so one 30-day eSIM can cover Japan plus onward stops. Browse destinations or read the setup guides before you fly.
Why trust VoaSim?
Registered company with an invoice on every purchase, USD payment via Stripe with no hidden fees, human support and a guarantee: if the eSIM will not connect and support cannot fix it, you get 100% back.