How to Avoid Roaming Charges in Thailand

You land at Suvarnabhumi or Phuket Airport, turn on your phone, and within seconds your Australian carrier has connected you to a Thai network. If data roaming is on, you're already being charged — before you've even left the terminal. Here's how Australians can stop that from happening.

What's actually happening when your phone "roams"

When you arrive in Thailand with your Australian SIM active, your phone automatically connects to a Thai network (AIS, TrueMove H or dtac) as a roaming partner of your carrier. Any data your phone uses — background email sync, push notifications, weather updates — flows through that network, and your carrier bills you for it at roaming rates.

The charge starts the moment data flows, not when you open an app. Your phone uses data in the background even when you're not touching it.

The two-line solution

The fix is to run two profiles on your phone at the same time:

• Your Australian SIM stays installed for calls and SMS — but with data roaming turned off.
• A Thailand eSIM handles all your mobile data — Grab, Google Maps, WhatsApp, browsing — at local rates, not roaming rates.

Your Australian number still works for incoming calls and SMS. Your data just goes through the eSIM instead. Check the compatibility checker to confirm your phone supports dual SIM.

Your first 10 minutes after landing

This is the routine that prevents charges:

1. Before you fly: buy and install your Thailand eSIM at home over Wi-Fi.
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 — the eSIM connects to the Thai network, and your Australian SIM stays active for calls and SMS without using data.

Done. Your data flows through the eSIM, not your carrier's roaming partner. For detailed installation steps, see the installation guide.

Keeping banking 2FA working

Many Australians rely on SMS for banking verification codes. Whether you can receive SMS while in Thailand depends on your carrier and plan — some allow it while roaming (sometimes at a cost), others require a specific add-on.

Check your carrier's roaming terms before you travel. If 2FA is critical for your trip, test receiving an SMS before you leave Australia. On a dual-SIM phone, you can generally keep your Australian SIM active for SMS while the eSIM handles data.

Mistakes Australians make with Thai roaming

• Leaving data roaming on after landing — the single most common cause of unexpected charges.
• Not installing the eSIM before departure — fumbling with QR codes at the airport is stressful and risks using roaming data while you set up.
• Assuming Airplane Mode is enough — you still need to turn on the eSIM line and turn off data roaming on the Australian line.
• Forgetting that background apps use data — email, photos, and cloud backups can trigger roaming data before you've switched to the eSIM.

Choosing a Thailand eSIM

Roamza offers Thailand eSIMs with unlimited daily options — 1GB of high-speed data per day, then unlimited data at a reduced speed. See the Thailand plans page for current options, or our best Thailand eSIM guide for a detailed comparison.

For a breakdown of how much data you'll actually use, see our Thailand data usage guide.