SIM Cards, eSIM & WiFi in Bangkok
Thailand has some of the cheapest mobile data on Earth and excellent 5G in Bangkok. Getting connected takes ten minutes at the airport — here's how, and what it costs.
Tourist SIM cards
Three networks cover Thailand: AIS (widest coverage), TrueMove H and dtac (now merged under True Corporation). All run counters in the arrivals halls at Suvarnabhumi and Don Mueang selling tourist SIMs — typically 8/10/15-day packages with generous or unlimited data plus some call credit, roughly 300–600 baht. Staff register and install it for you in minutes.
The passport rule
Thai law requires ID registration for every SIM: bring your passport to buy one, at the airport or anywhere else. Unregistered SIMs simply won't activate.
Buying in town
7-Eleven (they are literally everywhere — around 5,000 branches in greater Bangkok) sells SIMs and top-ups; official AIS/True shops in every mall handle bigger packages and eSIM. Top-up via 7-Eleven counter, network apps, or convenience-store kiosks.
eSIM
All three networks sell tourist eSIMs online for install before you fly; international eSIM marketplaces (Airalo, Holafly and similar) also cover Thailand — convenient, though usually pricier per GB than a local tourist SIM.
Speeds & coverage
Bangkok has dense 4G/5G; data is fast in the whole city, on the BTS/MRT, and in most of the country. Speedy enough for video calls from a khlong boat — a genuinely Bangkok experience.
WiFi
Free WiFi is standard in hotels, malls, and virtually every café — Bangkok's café culture doubles as a co-working network (Ari and Charoenkrung are laptop-friendly quarters). Public hotspot networks (AIS, True) exist but a data SIM is simpler and more secure. On public WiFi, prefer HTTPS sites and avoid banking.
Apps worth installing
Grab/Bolt (rides & food), ViaBus (live buses), Google Maps offline area for Bangkok, LINE (Thailand's default messenger — businesses often list a LINE ID instead of email), and your bank's app for verification while abroad.