eSIM and SIM cards in Thailand
Thailand is easy to get online. AIS covers islands and hills better. True-dtac is fine in cities. Install a tourist eSIM before you fly if the phone allows it. Otherwise buy a SIM after immigration and register it to your passport.
Thailand has two networks that matter for a first trip. AIS is the wider rural and island net. True and dtac merged into True Corporation; tourist plans now sit under a shared True-dtac shop even when the sticker still says Happy Tourist. National Telecom is not a tourist counter.
Keep the home SIM in a second tray or eSIM slot if you need bank codes. A Thai number helps Grab, hotel desks, and boat operators. A data-only travel eSIM is enough for maps and not enough for some Thai OTP messages.
What the tourist counters actually sell
| Brand | Useful tier | What you get | Who it fits |
|---|---|---|---|
| AIS Lucky / tourist eSIM | 8 days 499 THB, 15 days 699, 30 days 1,199, 60 days 1,599 | Unlimited data at max available speed on the tourist tiers, plus in-net calls on many packs | Koh Tao, Lanta, Lipe, Pai, Cheow Lan roads |
| True-dtac Tourist Infinite | 8 / 15 / 30 days at the same 499 / 699 / 1,199 headline | Unlimited 5G/4G at max available speed, local calls with a 15-minute cap per call on some packs | Bangkok, Chiang Mai, Phuket town, if you never leave the corridor |
| True-dtac cheaper tourist | 10-day data-only or older Happy packs | Data, inbound calls. Outbound voice can be off on data-only | A week in malls. Read the card before you leave the desk. |
| Global travel eSIM (Airalo and similar) | Priced in your home currency | Data only, no Thai number | Fine for maps. Weak for boat operators who want a callback. |
Where to buy
Physical SIMs: Suvarnabhumi arrivals (dtac has listed gate 7 on the second floor of arrivals), Don Mueang between terminals 1 and 2, Phuket terminal 2, Samui near gates 6 and 7 on departures. Hours are not a promise. Check on arrival. 7-Eleven sells tourist packs and still wants the passport at the till.
eSIM: AIS and True both sell the same tourist tiers as eSIM. Registration still happens, in the app or at a shop. The queue you skip is the airport laminate desk, not the identity rule.
Ignore blogs that still say airport SIMs are always double the city price. The official 8 / 15 / 30 day Infinite ladders match in town. What you overpay for is a confused reseller and a pack you did not read.
Keep going
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Common questions
- AIS or True-dtac?
- AIS if any island, loop road, or national park is on the trip. True-dtac if you will live on BTS and a mall 5G cell.
- Do you need a Thai number?
- Yes if boats, hotels, or Grab OTP will call you. No if you only need maps and you already have WhatsApp on wifi.
- Can you register more than one SIM?
- NBTC caps tourist SIMs at three per person per brand. Do not collect drawers of dead tourist packs.