Roaming or an eSIM in Thailand: what changes
Roaming keeps your home line working in Thailand at your carrier's rates. A prepaid eSIM gives you a separate data line that cannot add charges.
- Prepaid, no extra charges
- Data roaming only if needed
- Home line stays on
The short answer
Roaming on your home line charges your carrier's rates in Thailand. The eSIM from this site is prepaid: you pay once, it runs on a Thai network, and it cannot add charges. Data roaming stays off on both lines; switch it on for the eSIM line only if the line does not connect.
Checked October 2, 2026
Home roaming against an eSIM
Cost
- Roaming on your home line
- Your carrier's roaming rates
- eSIM from this site
- Paid once, when you buy the plan
Extra charges
- Roaming on your home line
- Possible, depending on your carrier
- eSIM from this site
- None: the plan is prepaid
Setup
- Roaming on your home line
- Nothing to install
- eSIM from this site
- Set it up at home; turn it on once you land
Data roaming switch
- Roaming on your home line
- Keep it off
- eSIM from this site
- Keep it off; on only if that line will not connect
Your number
- Roaming on your home line
- Your own, at your carrier's rates
- eSIM from this site
- Your own stays on; a Thai number if the plan says so
Which switch goes where
For the eSIM line: switch it on and set it for mobile data. Keep data roaming off and only turn it on for that line when it will not connect: that is the store’s own guidance. On the home line, leave data roaming off so no charges can build up, and leave the line on if you want calls and texts to reach you. Anything that reaches your home number as a call or text is billed by your home carrier.
The plan for this trip
Lowest price per day for trips of 8 to 15 days
10 days · 50 GB · US$9.88
Data only, tax included. Each plan names its Thai network before you pay.
Buy on VietSIMQuestions
Do I need a shop for the eSIM?
No. The eSIM is bought online before you fly, and the QR code appears on screen right after payment; save the page link, because it is where your code is kept. A SIM card bought in Thailand is registered at the point of sale, and the shop asks for your passport.
When is data roaming needed on the eSIM?
Only if the line does not connect. The plans run on Thai networks, so the switch normally stays off; the store names it as the fix for a line that will not start, and a prepaid plan cannot add a charge because of it.
Sources
Where the facts on this page come from.
Get your Thailand eSIM before you fly.
Plans from US$4.88, tax included, on dtac, True or a Southeast Asia regional network. Pick one here and pay on the store in US dollars.
See the plansCheckout on VietSIM · full refund if it does not work