Thailand is one of the cheapest countries in the world for mobile data, which raises a fair question: why not just buy a tourist SIM at the airport? You can, and for long stays it is a good option. For most holidays, though, an eSIM installed before you fly costs about the same, skips the counter and the passport scan, and keeps your home number live for bank codes.
The networks
Thailand has two large mobile groups: AIS and True (which absorbed dtac in 2023). Both cover Bangkok, Chiang Mai, Phuket, Krabi and Koh Samui with 4G and 5G, and both reach the smaller islands and the ferry routes with usable 4G. Travel eSIMs connect to one of them as a roaming partner. Coverage differences only show on remote islands and in the northern hills; near the beaches and in the cities, either network is fine.
Tourist SIM vs travel eSIM
A tourist SIM from AIS or True at Suvarnabhumi or Phuket airport is cheap and comes with generous data, but you register it with your passport, you swap your physical SIM out (or use a dual-SIM slot), and it is tied to that trip.
A travel eSIM costs a little more per gigabyte at small sizes and about the same at larger ones. It is installed at home, works the moment you land, and leaves your home SIM in place. If you are hopping on to Vietnam or Indonesia, an Asia regional plan covers the whole route.
How much data for Thailand
Beach holidays use less data than city trips. Count on:
- 300 to 500 MB per day for messaging, maps to the night market and a few photo uploads.
- 1 GB per day or more if you stream, make video calls home or work from the hotel.
For two weeks, 5 to 10 GB suits most visitors. Thailand plans are often sold as daily allowances as well as fixed volumes; a daily allowance resets each day and suits streaming, a fixed volume suits light, uneven use.
Current prices
At the time of writing, the Thailand listing on esimlist.com shows 61 plans from five providers, including BNESIM, Maya Mobile, Ubigi, UPeSIM and Yesim. The cheapest is a 500 MB plan for $2.74 and the largest is 150 GB for 30 days at $79. Sort by price per GB to see which brand is actually cheapest at the size you need.
Tips
- Hotspot: most plans allow tethering, which matters if you work from a laptop. The plan page says so.
- Grab and food delivery apps need a working data connection the moment you land; an eSIM that is already installed gives you that at the taxi rank.
- Signal on the islands can drop on boat crossings; nothing to fix, it comes back at the pier.