You landed in Bangkok, turned on your phone and… nothing. Roaming fees of EU operators in Asia are astronomical (one megabyte can cost as much as 9 euros!). Therefore, the first task of every traveler is to get local data.
Thailand has one of the best mobile networks in the world. You can even get a 5G signal on remote islands. So the question is not "if" but "which" card to choose.
Technology has advanced and today you have two main options to choose from.
1. eSIM (Virtual Card) – For the Convenient
This is a state-of-the-art solution. You don't have to put anything on your phone, just scan the QR code (often at home in your country) and the internet will turn on automatically upon arrival.
Benefits of eSIM
Maximum convenience. Your EU SIM remains in your phone (to receive SMS from the bank), you use the Thai eSIM only for data.
Disadvantages of eSIM
Many international eSIMs (e.g. Airalo) are data only. This means you don't have a Thai phone number.
Why is this a problem?
Without a Thai number, a Grab or Bolt taxi driver won't let you in if they can't find you. Also, signing up for some local apps requires a verification SMS to a Thai number.
A good old classic that you can buy at the airport or in a store.
Advantages
You always get a Thai phone number (including calling credit), it's usually cheaper and offers more data.
Disadvantages
You need to pick out your EU SIM card (and don't lose it!).
Tip: If you have an eSIM-enabled phone, the best option is to buy a local Thai eSIM directly from the operator at the airport. This way you get the best of both worlds - you have a Thai number and a free slot for an EU card.
There are three main players in Thailand. Prices and coverage are very similar, so you can’t go wrong with any of them.
AIS: Market leader
It has the best coverage on remote islands and in the mountains. If you plan to go off the beaten track, get AIS.
TrueMove H
A very strong player with excellent 5G speeds in cities. Often has the best promotions at 7-Eleven stores.
DTAC
Popular with tourists, good coverage in resorts, but can occasionally drop out in the jungle.
Where to buy a SIM card and how much does it cost?
This is where tourists make the most common mistake and overpay unnecessarily.
A) At the airport (Convenient, but more expensive)
Immediately after arrival you will see the operators’ stands. They sell special “Tourist SIM” packages.
The price is around 299 THB (8 days), 599 THB (15 days) to 1000+ THB (30 days).
Verdict: You will pay a “convenience tax”. It is fast, the staff will set everything up for you, but for the same price you would have twice the data in the city.
B) At the 7-Eleven store (Golden Mean)
When you leave the airport, head to the nearest "Seven".
Procedure: Ask for a SIM card at the cashier (most of them have TrueMove). They will ask for your passport to scan and take a photo of your face (mandatory registration).
Price: You can buy regular local packages here, which are cheaper. For example, 30 days of unlimited internet (with limited speed, but enough for regular surfing) can cost you only 300-400 THB.
C) Official stores in shopping malls
If you want a specific package or eSIM from AIS/True, go to a shopping mall (e.g. Central Festival, Terminal 21). They will sell you cards at local prices, not tourist prices. This is the cheapest option, but it takes time.
Important Notice: Grab and Bolt Apps
You need internet in Thailand mainly for transportation. The Grab and Bolt apps (Asian versions of Uber) are a must to avoid being ripped off by local taxi drivers.
You will receive an SMS to register for Bolt. Therefore, it is ideal to activate the app at home on an EU number, or buy a SIM with a local number in Thailand.
Taxi drivers in Thailand rarely speak English. If you have internet, the app will automatically translate the chat between you and the driver.
If you want maximum comfort and don't mind the higher price: Buy an eSIM (e.g. Airalo) at home. (Be careful, usually without a number).
If you want the best price/performance ratio: Buy a physical SIM card (or eSIM) from AIS or TrueMove directly in Thailand (at a 7-Eleven or a shopping mall).
Always have your passport with you when buying a SIM card.