Switch your Thailand eSIM on when you land
- Line on
- Mobile data on the eSIM
- Roaming only if needed
The short answer
Once you land, switch the eSIM line on and set it as the mobile data line. When data does not start, enable data roaming on the eSIM line and try again. Leave data roaming off on your home line so nothing can run up charges.
Checked October 2, 2026
On the eSIM line
Switch the line on and set it as the mobile data line (on an iPhone: Cellular Data). When data does not start, enable data roaming on the eSIM line and try once more. Disable the automatic switching of mobile data between lines so the phone cannot fall back to your home line.
On your home line
On your usual SIM, switch data roaming off. The line can stay on for calls and texts to your own number; your home carrier bills those as usual.
Give it a minute
Finding the network can take the phone a few minutes. The signal bars and the network’s name appear next to the eSIM line: one of Thailand’s networks, AIS, TrueMove H or NT.
If it fails (Switch it on after landing)
Go through not connecting step by step. The install window is 30 days from purchase; if your trip begins after it closes, contact the store’s support before installing.
More help
Install your Thailand eSIM at home, before you fly
Scan the QR code from your order page at home on Wi-Fi, within 30 days of buying, and keep the line off until you land. How to install a Thailand eSIM.
Data roaming on a Thailand eSIM: when you need it
The eSIM runs on a Thai network, and the store says switch data roaming on for the eSIM line only when it does not connect. Where the switch is.
Thailand eSIM not connecting: the checks, in order
Is your eSIM not working in Thailand? Check the line, mobile data and airplane mode, then data roaming, pick the network by hand, and write to support.
Thailand eSIM refunds: when you get your money back
When the eSIM does not work and we cannot fix it, the refund is full. A working eSIM is not refunded. How to ask, and where the money goes.
Can my phone take an eSIM? Check it before you buy
Dial *#06#: if your phone shows an EID, it has an eSIM. It must also be unlocked. Check your model before you buy a Thailand eSIM.
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