The best eSIM for Thailand
Thailand is the cheapest of the popular long-haul destinations for travel data, by a clear margin. The same providers that charge £50 or more for a month in Japan or the US will do Thailand for a good deal less, because local wholesale data is cheap and competition is fierce.
It is cheap, so buy for the trip rather than the week
Because the prices are low, the usual advice to buy the smallest plan that will do is weaker here. The step up from a short plan to a month is often small enough that it is not worth the risk of running out halfway through. Airalo's 30-day unlimited Thailand plan was £37.50 when we checked it on 4 September 2026, against £16 for seven days, so a three-week trip costs barely more than two one-week plans.
Prices move, so treat that as an illustration and check the live table.
Coverage: the mainland is easy, the islands less so
Bangkok, Chiang Mai and the main tourist routes have excellent coverage on all three Thai networks, AIS, TrueMove and dtac. The gaps show up on the smaller islands, on boats between them, and in the national parks. If your trip is island-heavy, that is a reason to prefer a provider that uses AIS, which generally has the widest rural and island reach, though no travel eSIM company guarantees which network you land on.
Unlimited plans and the daily cap
The same pattern as everywhere: an unlimited Thailand plan almost always means a full-speed daily allowance and then a slowdown. Airalo gives 3GB a day then 1Mbps, Saily gives 5GB a day, Nomad gives 2GB a day then 512kbps. For a beach holiday, any of those is more than enough. For working remotely, the difference between 2GB and 5GB a day is the whole decision.
Worth knowing
- Most Thailand travel eSIMs are data-only, so you will have no Thai number. Grab, Foodpanda and most booking apps work fine on a foreign number, but a few local services will want a Thai one.
- Buying locally is genuinely competitive here. Tourist SIMs sold at Suvarnabhumi and Don Mueang airports are cheap. An eSIM wins on convenience and on landing with data already working, not always on price.
- Install before you fly. Airport Wi-Fi in Bangkok is fine but the queue at the SIM counter is not.