The main carriers are AIS, True, Dtac. 5G in Bangkok and strong 4G on the tourist islands. On boat trips between islands the signal fluctuates in open water.
A travel eSIM like VoaSim uses those same towers: coverage is that of the local networks.
| Option | How it works in practice |
|---|---|
| Travel eSIM | Bought online before the trip, arrives by e-mail and connects on landing. Unlimited from USD 1.79/day at VoaSim, no paperwork or queues. |
| Local SIM | Tourist SIMs from AIS, dtac or True cost THB 300-600 (USD 10-20) at the airport, with passport registration at the counter. It is one of the countries where the local SIM is cheapest and simplest. |
| Your carrier's roaming | Convenient but with a daily cost that piles up, and passes usually carry few GB or fair use. Check the exact rate in your app before flying. |
| Wi-Fi only | Free, but leaves you without maps, translator or rides on the street — exactly where you need them most. |
Bangkok, Chiang Mai and the big islands have solid 4G/5G. On small islands and jungle areas signal depends on the carrier: AIS usually has the best rural coverage. Grab (transport) and translators make data essential.
Suvarnabhumi has free Wi-Fi and 24h SIM counters, but with notorious queues at peak arrival times. The eSIM removes the queue; the local SIM is a decent plan B if your phone has no eSIM.
| Days | Price | Per day |
|---|---|---|
| 5 days | USD 18.90 | USD 3.78/day |
| 7 days | USD 23.90 | USD 3.42/day |
| 10 days | USD 30.90 | USD 3.09/day |
| 15 days | USD 42.90 | USD 2.86/day |
| 30 days | USD 61.90 | USD 2.07/day |
| 60 days | USD 106.90 | USD 1.79/day |
Today's promo prices, the same in 160+ countries. Second eSIM in the same order gets an extra 10% off.
Bangkok, Phuket, Chiang Mai, Krabi, Koh Samui and the whole territory with local network coverage. More details on the eSIM for Thailand page.
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