Thailand eSIM help: setup, fixes and straight answers
Everything about the Thailand eSIM from this site: the setup at home, the switch after landing, the fixes and the refund rule.
- Install within 30 days
- Data roaming only if needed
- QR code right after payment
- Full refund if it does not work
The short answer
Set the eSIM up before you fly, at home on Wi-Fi. In Thailand, switch the line on and make it the one for mobile data; turn on data roaming for it only if it will not connect. An eSIM that fails and cannot be fixed is refunded in full.
Checked October 2, 2026
What do you need?
Install the eSIM
Install within 30 days of the purchase: scan the QR code at home on Wi-Fi.
OpenSwitch it on in Thailand
The order of the switches, once you land in Thailand.
OpenData roaming
Where the switch lives, and when it matters.
OpenNot connecting
The checks in order, and how to reach support.
OpenRefunds
What can be refunded, and how to ask.
OpenCheck your phone
Find out in a minute: dial *#06# on your phone.
Open
Set up your eSIM in four steps
Check your phone
Your phone needs eSIM support and must be unlocked. Dial *#06#: an EID shows an eSIM is there.
Buy a plan
Pick the days and the data on the store. Every plan names its network, and the total, tax included, is shown before you pay.
Install at home
Open the order page on Wi-Fi and scan its QR code within 30 days of purchase. The code appears right after payment, so keep the page link.
Switch it on in Thailand
Bring the line up and make it your mobile data line; when it will not connect, enable data roaming on the eSIM line.
eSIM or a SIM card bought in Thailand: which fits you?
Where you get it
- This eSIM
- Online, before you fly
- A SIM card bought in Thailand
- At an airport counter or a shop in Thailand
- Roaming on your home line
- Your home carrier
What it costs
- This eSIM
- From US$4.88, prepaid
- A SIM card bought in Thailand
- Set at the counter, in baht
- Roaming on your home line
- Your carrier's roaming rates
What you show
- This eSIM
- Nothing to show at a counter
- A SIM card bought in Thailand
- Passport, registered at the counter
- Roaming on your home line
- Nothing
Your number
- This eSIM
- Stays on in your phone; the plans say whether they include a Thai number
- A SIM card bought in Thailand
- A new Thai number
- Roaming on your home line
- Your own
When it is ready
- This eSIM
- Set it up before you fly; turn it on in Thailand
- A SIM card bought in Thailand
- After you find a counter and buy it
- Roaming on your home line
- As soon as roaming is switched on
Data
- This eSIM
- Named on the plan, in total
- A SIM card bought in Thailand
- Named on the counter's packages
- Roaming on your home line
- Your carrier's allowance
Coverage in Thailand: what to expect
Thailand has three mobile networks: AIS, TrueMove H and NT. TrueMove H belongs to True Corporation, which completed its merger with dtac in 2023; NT, National Telecom, is the state-owned operator, formed by merging TOT and CAT. Each network publishes its own coverage map, so check the map for the places you are going. An eSIM for Thailand runs on a Thai network, and that network's name appears next to the eSIM line once it connects.
Registration: the passport step for Thai SIMs
A Thai SIM card bought in person is registered to the buyer's passport at the counter. This eSIM is bought online and delivered as a QR code, and nothing on this site asks you for a passport in advance. If a plan carries a registration step, it is stated on the plan before you pay.
Troubleshooting
The QR code will not scan
Make sure Wi-Fi is on, then try the scan from a second screen, or type the details from the order page by hand. On some phones the eSIM must be added from settings, not through the camera.
The eSIM is in, but the signal is missing
Check that the eSIM line is on, then toggle airplane mode. Give the phone a few minutes to find the network.
There is signal, but no data
Set the eSIM line as the one for mobile data. If data still does not start, enable data roaming on that line: the store names this switch as the fix when a line will not connect.
Data works, then stops
Open your order page: once the days or the data on the plan run out, mobile data can slow or stop until the plan ends.
My home SIM keeps getting the data traffic
Make the eSIM line your mobile data line, and disable automatic switching of mobile data between lines so the phone will not fall back to the home line.
I deleted the eSIM by mistake
Contact the store's support with the link to your order page before doing anything else. A QR code is usually good for one install only.
Nothing worked and the line is still down
Write to the store's support with your order page link and your phone model while you are still in Thailand. If it cannot be made to work, you get a full refund.
Refunds: what can be refunded
An eSIM that fails and cannot be fixed is refunded in full by the store. Change of mind is not a refund reason on a working eSIM, and neither is a phone that cannot install it.
If the eSIM does not work and we cannot fix it, you get a full refund.
Still stuck?
Orders, QR codes and refunds are handled by VietSIM support. Write with the link to your order page and your phone model.
contact@vietsim.com
Quick answers
What does a plan name before I pay?
Its Thai network, one of AIS, TrueMove H or NT; the data and the days; whether it includes a Thai number; and its price in US dollars with tax.
Does the eSIM have a phone number?
The plan says whether it includes a Thai number, before you pay. Your own number stays on in your home SIM.
Should data roaming be on?
For the eSIM line alone, and only when it will not connect: the store's guidance is to switch roaming on there when a line does not start. Leave it off on the home line.
When should I install it?
At home, over Wi-Fi, and within 30 days of purchase. Leave the line off until you land in Thailand.
Can I use WhatsApp on my own number?
Yes. Your number stays as it is, and WhatsApp simply runs on the eSIM's data.
Who answers if something goes wrong?
The store where you paid. Send its support the link to your order page.