Thailand runs on your phone: taxis and delivery via Grab, QR payments, a translator to talk to drivers. After a long flight it's best to leave the airport already online.
Networks and coverage
The largest operators are AIS and True (merged with dtac). Bangkok, Phuket, Pattaya, Chiang Mai and popular islands — Samui, Phangan, Krabi — have excellent 4G and 5G. Small islands and the jungle have weaker coverage.
eSIM, local SIM or roaming
A local SIM is bought on arrival, roaming without a package is expensive, while an eSIM takes a minute to buy from home: the QR code arrives instantly and your main number stays on for calls and texts. Worth knowing in Thailand:
- Tourist SIMs are sold at the airport with a passport — not fun after a 9–10 hour flight.
- Grab is the main way to get around: the fare is fixed upfront, no haggling.
- Travelling across several Asian countries? Check the regional plan.
How to prepare before you fly
- Check eSIM support: dial
*#06#— if you see an EID line, you're good. - Install the eSIM at home over Wi-Fi. For most plans the clock starts at the first connection abroad; the exact rule is on the plan card.
- Set the eSIM as your mobile data line and turn on data roaming for it.
- Turn off data roaming on your main SIM so it doesn't spend money.
Step by step, with videos: How to install an eSIM on iPhone and Android.
Trip tips
- Install Grab and Bolt before the trip.
- The translator in the ALO eSIM app helps with drivers and pharmacies.
- Download an offline map before going to a small island.
The ALO eSIM app also has a translator and a map: ask for directions, explain yourself at a pharmacy, find a café nearby.