How to Avoid Roaming Charges in Japan

If you're travelling from Australia to Japan, your phone can connect to a Japanese mobile network as soon as you arrive. If your Australian SIM is allowed to use roaming data, that can lead to unexpected charges — sometimes $5–$10 per day depending on your carrier and plan.

The good news is there's a straightforward alternative: use a travel eSIM for mobile data while keeping your Australian SIM in place for your normal number.

Why roaming charges happen in Japan

International roaming is what happens when your Australian carrier routes your data through a Japanese partner network. Your carrier charges you for that data — often as a daily fee or per-megabyte rate.

The main Australian carriers (Telstra, Optus and Vodafone) offer international roaming, but the costs can add up quickly over a trip. Check your carrier's current international roaming rates before travelling — rates and zones vary by carrier and destination.

How a travel eSIM avoids roaming charges

A travel eSIM is a separate data plan installed on your phone. When you land in Japan, you switch on the eSIM for mobile data and turn off data roaming on your Australian SIM. Your data goes through the eSIM, not your Australian carrier's roaming partner — so you don't incur roaming charges.

For Japan eSIM plan options, see the Japan plans page or our best Japan eSIM guide. To work out how much data you actually need, see our Japan data guide.

Setting up dual SIM for Japan travel

On a compatible dual-SIM phone, you can run two SIM profiles at the same time — your Australian SIM and a Japan eSIM. The typical setup is:

• Australian SIM — your normal Australian mobile service and phone number, installed as usual.
• Japan eSIM — a travel data plan installed as a second profile, used for mobile data while in Japan.

This lets you keep your Australian number for calls and SMS while using the eSIM for data. See the compatibility checker to check if your phone supports dual SIM.

Preventing accidental data roaming

The most common cause of unexpected roaming charges is forgetting to turn off data roaming on your Australian SIM. Here's the routine:

1. Before you fly: buy and install your Japan eSIM.
2. On the plane: turn on Airplane Mode.
3. After you land: turn on the eSIM line for mobile data.
4. Turn off data roaming on your Australian SIM line.
5. Turn off Airplane Mode (or leave it on and turn on the eSIM line — the eSIM will connect to the Japanese network).

This ensures your data goes through the eSIM, not your Australian carrier's roaming.

For detailed setup steps, see the installation guide.

SMS and 2FA considerations

Many Australians rely on SMS for banking 2FA and other verification codes. Whether you can receive SMS while in Japan depends on your carrier, your plan and your device settings.

Some carriers allow SMS reception while roaming (sometimes at a cost), while others may require a specific roaming add-on. Check your carrier's roaming terms before you travel, and test receiving an SMS before you leave if 2FA is critical for your trip.

On a dual-SIM phone, you can generally keep your Australian SIM installed and active for SMS while using the eSIM for data. But the exact behaviour depends on your carrier and device — check both before you travel.

What about calls and texts?

If you need to make or receive calls and texts on your Australian number while in Japan, check your carrier's roaming rates for voice and SMS. Some carriers include calls and texts in a daily roaming pack; others charge separately.

For data, the eSIM handles everything — maps, messaging apps, social media and browsing — without incurring roaming charges.

Why buy before you fly?

Buying and installing your Japan eSIM before you leave Australia means you land ready to connect. You can load Google Maps, message your hotel and use translation apps the moment you clear customs at Narita, Haneda or Kansai.

Japan eSIM plans

Roamza offers Japan eSIMs with unlimited daily options. Unlimited plans include a daily high-speed allowance followed by unlimited data at a reduced speed. See the Japan plans page for current options.