In short
Yes, you can, and receiving SMS abroad is free if you do three things:
The one thing to watch: answering calls on your Thai number costs money at that country's roaming rate.
Why you still need your Thai number abroad
Most transfers in Thai banking apps don't need an SMS, but some things still send a one-time code (OTP) to your Thai number:
You can't know in advance when you'll need it, so set things up to receive SMS for the whole trip.
Step 1: turn on roaming before you fly
Turning on the roaming service is not the same as buying a roaming data pack. The service is free, and your carrier sends an SMS to confirm it.
| Carrier | How to turn on the roaming service |
|---|---|
| AIS | Dial *125*1# and call, or in the myAIS app: Profile → Manage network → Roaming service |
| True / dtac | In the True or dtac app (roaming settings). Prepaid customers can dial *118*001# while still in Thailand |
Forgot before your flight? You can still turn it on in your carrier's app abroad, using the travel eSIM's data or Wi-Fi.
Step 2: set up your phone so data doesn't leak
This is the step that matters. Get it wrong and the phone can quietly use your Thai SIM's data, which is very expensive abroad.
iPhone
Apple describes Data Roaming as using internet data on foreign networks, so receiving SMS on your Thai SIM doesn't need its Data Roaming on.
Android
Menu names differ by brand. On Samsung it's Settings → Connections → SIM manager.
Many Android phones turn Data Roaming on or off for all SIMs at once. If you need it on for the eSIM, also switch off mobile data for your Thai SIM in your carrier's app, so you're sure you won't pay for roaming data.
If your Thai SIM shows no signal
What costs money
| On your Thai SIM | Cost |
|---|---|
| Receiving SMS (including OTP) | Free |
| Answering calls | Charged at that country's roaming rate |
| Making calls / sending SMS | Charged |
| Using data | Charged, and expensive: Step 2 prevents it |
If someone calls your Thai number during the trip and it isn't urgent, don't answer. Call back over WhatsApp, LINE or FaceTime on the eSIM's data instead.
Banking app tips
If you'd rather not use an eSIM
A Thai carrier's roaming pack also works for OTP, because one SIM handles both data and SMS. It's simpler but usually costs more than a travel eSIM, so it suits short trips or phones without eSIM.
Going to Japan or Korea? Our guides compare every plan: Japan eSIM and Korea eSIM.
Not sure your phone supports eSIM? See how to check and install an eSIM, or pick a plan for your destination on all destinations.
