Travel eSIM or international roaming? What Australians should compare
Short answer: international roaming keeps your Australian service working overseas, including calls and texts, usually for a daily fee. A prepaid travel eSIM adds a separate data-only line for a fixed price. If you mainly need maps, messaging and bookings, a travel eSIM can be a simpler way to control cost. If you need to make and receive normal calls on your Australian number all day, roaming may suit you better. You can also use both: the travel eSIM for data, and your Australian SIM left on for texts.
What each option includes
| Roaming day pass from your Australian carrier | Prepaid travel eSIM (data-only) | |
|---|---|---|
| What you get | Data, calls and SMS on your own number, within the pass allowance | Mobile data only; no new phone number |
| How you pay | A fee for each day the service is used overseas | One upfront price for a set amount of data and days |
| Your Australian number | Works as normal | Stays on your Australian SIM; the eSIM only carries data |
| Set-up | Turn the pass on with your carrier before you fly | Install the eSIM on Wi-Fi before you fly, switch it on at your destination |
| Phone needs | Any phone on your plan | An eSIM-compatible, carrier-unlocked phone |
How roaming charges start
Read your carrier's current roaming page before you travel, because terms change. As an example, Telstra's International Roaming Day Pass page (checked 16 October 2026) says:
- a Day Pass in its Zone 2, which includes Japan, Indonesia, Thailand and the USA, costs $10 per day and includes 2GB of data, plus unlimited standard calls and SMS;
- the daily charge applies on days your service is used overseas to make or receive calls, send an SMS or use data, including background data. Receiving an SMS does not trigger the charge;
- a Day Pass can take up to 2 hours to activate, so Telstra suggests turning it on before you fly.
Optus and Vodafone publish their own roaming options and prices. Check them directly for the destinations you are visiting.
The background-data point matters. Apps refresh in the background, so if your Australian line has data roaming switched on, a day can become chargeable without you opening a browser.
Worked example: 10 days in Japan
This is arithmetic from published prices on 16 October 2026, not a measurement of how much data you will use.
| Option | Data | Calls and SMS | Price for 10 days |
|---|---|---|---|
| Telstra Zone 2 Day Pass, used every day | 2GB per day | Included, on your number | $10 × 10 days = $100 |
| Telroo Japan travel eSIM, 20GB for 30 days | 20GB in total | Not included (data-only) | A$17.90 |
The two are not the same product: the day pass includes calls and texts on your own number, and the eSIM does not. If you rarely make standard calls overseas and use WhatsApp, FaceTime or similar apps over data instead, the data-only option may be enough. If you would rather have a daily allowance, our Japan daily plans come in 1, 7 or 30 days. Prices on our product pages are the current ones; the figures above may have changed since this guide was written.
Which should you choose?
A travel eSIM tends to suit you if:
- you mainly need data for maps, ride-share apps, messaging and bookings;
- you want a fixed, upfront cost for the trip;
- your phone is eSIM-compatible and unlocked (check here).
Roaming tends to suit you if:
- you need to make and receive standard calls on your Australian number throughout the trip;
- your phone does not support eSIM or is locked to your carrier;
- your plan already includes roaming for your destination at no extra cost.
Using both without surprise charges
- Install the travel eSIM on Wi-Fi before you leave (installation guide).
- When you land, set the travel eSIM as your mobile data line.
- Turn off data roaming on your Australian line, and turn off any setting that lets the phone switch data between lines automatically (on iPhone this is "Allow Mobile Data Switching").
- Keep your Australian line switched on if you want to receive texts, such as bank codes. Check your carrier's terms for what receiving calls or texts costs where you are.