Internet in Thailand for Tourists: eSIM, SIM, Coverage

Internet in Thailand for tourists comes down to two options: a local tourist SIM from AIS or True-dtac, which needs your passport and a live face check at the counter, or a travel eSIM you install at home and switch on after landing. Matrimix sells data-only eSIMs for Thailand in its Telegram wallet, paid from the wallet balance without a bank card or passport.

Key facts (October 2026)

• Two networks, three brands. AIS is one network; TrueMove H and dtac are two brands of True Corporation, which merged in 2023 and finished combining the two networks in 2025.
• Tourist SIMs need an original passport. Since 18 August 2025 every new SIM registration in Thailand includes a real-time face check, according to the regulator NBTC.
• Tourist SIMs are capped at 60 days and cannot be extended by topping up; foreigners may register at most three numbers per operator.
• Islands: big islands such as Phuket and Koh Samui are well covered around towns and beaches; remote bays, jungle roads, national-park islands and boat crossings often have weak or no signal.
• Travel eSIM: no counter and no passport; current plans and prices: eSIM Thailand.

Thai mobile operators: AIS, TrueMove H and dtac

You will see three logos at the airport, but there are really two networks.

AIS runs its own network and tourist SIM counters at Suvarnabhumi, Don Mueang, Phuket, Chiang Mai, Samui and other airports. Its own shop list for Suvarnabhumi runs to more than thirty points on the arrivals floor.

TrueMove H and dtac have belonged to the same company, True Corporation, since the merger completed in March 2023. In October 2025 the Bangkok Post reported that True had finished pooling the two networks' towers and spectrum under its "one network" plan. Both brands still sell SIMs at the time of writing. Thai media report that the three-year commitment to keep both brands has ended and that True is considering the future of dtac, so the dtac logo may change.

For a tourist the practical difference between the brands is the package, not the network: since the integration, TrueMove H and dtac customers use the same infrastructure.

Tourist SIM or travel eSIM

	Thai tourist SIM (AIS, True, dtac)	Travel eSIM from Matrimix
Where you get it	Counter after passport control, operator shop, 7-Eleven	In Telegram, before the trip
Documents	Original passport and a live face check	None
Local phone number	Yes, Thai number	No, data only
Validity	Up to 60 days for tourist SIMs	Starts when the eSIM first connects in Thailand
Payment	Cash or card at the counter	Wallet balance in USDT/USDC; other coins are swapped automatically
Phone requirement	Any unlocked phone with a SIM slot	eSIM support and no carrier lock

A Thai SIM makes sense if you need a local number, for example for a long stay or for services that send codes by SMS. If you only need maps, messengers, taxis and booking apps, a travel eSIM saves the airport queue and keeps your home SIM in the phone for bank SMS.

SIM registration rules for tourists

Thailand has tightened SIM rules as part of its campaign against phone scams. In mid-2025 the NBTC board approved measures that limit foreigners to three numbers per operator, require a passport for registration and cap tourist SIMs at 60 days without extension by top-up. To keep using a number after that, you register again in person.

From 18 August 2025, the NBTC says, registration points must run real-time "liveness detection": the clerk scans your passport and you look into a camera. Photocopies or a photo of the passport are not accepted. Allow a few extra minutes at the counter, especially when several flights land at once.

A travel eSIM from Matrimix does not ask for a passport or ID; you pay from the wallet and get the eSIM in Telegram.

Coverage on the islands

Coverage in Bangkok, Chiang Mai, Pattaya and the main resort towns is generally good. On islands it depends on where exactly you are:

• Phuket, Koh Samui: developed islands, usually solid coverage in towns and on the main beaches.
• Koh Phangan, Koh Tao, Koh Lanta, Phi Phi: usable around towns and popular beaches; local guides report gaps on remote coasts and in the hilly interior, and slowdowns during big events.
• Small or protected islands (for example national-park islands visited on day trips): expect little or no signal.
• Ferries and speedboats: the signal often disappears over open water.

Download offline maps and save your hotel address before you board a boat. Which Thai network a travel eSIM uses can differ between plans, so check the plan details on the eSIM Thailand page if you are heading somewhere remote.

Before you go

1. Check your phone. Dial *#06#: an EID line means eSIM support. The phone must also be carrier-unlocked. The list of models is on compatible phones.
2. Buy the eSIM in Telegram. Open @MatrimixBot → Mini App → Services → Travel SIM cards, find Thailand under Popular or with the search. If you visit neighbours too, look at Regions: regional plans cover several countries, so check the list on eSIM Southeast Asia.
3. Pay from the wallet. The price is in USD and shown before you confirm. USDT and USDC pay directly; another coin on the balance is swapped automatically at the quoted rate.
4. Install at home over Wi-Fi. You get a QR code, manual entry details (SM-DP+ address and activation code) and, on iPhone with iOS 17.4 or later, a one-tap install button. The order is also saved under Profile → Purchases.

Validity starts when the eSIM first connects to a network in Thailand, not at purchase or installation. Use it on the trip you bought it for.

On arrival

Switch mobile data to the eSIM line and turn on data roaming for that line. Keep your home SIM on for calls and bank SMS if you like, but turn its data off to avoid roaming charges. Data left is shown on the order page in the Mini App. Hotspot usually works, though on some networks it can be limited.

Good to know

• Data only. No Thai number, no calls, no SMS. Call through messengers.
• New plan instead of a top-up. If data runs out, buy another plan (a new eSIM) in a couple of taps.
• One installation. Do not delete the eSIM profile until the trip is over; a bought eSIM cannot be returned. A failed order is refunded to the balance automatically.
• Telegram needed. The store lives in the Matrimix wallet in Telegram.
• Matrimix holds your balance for you. No seed phrases and no extra apps — everything opens in Telegram.
• Phone compatibility. The phone needs eSIM support and no carrier lock — check with *#06# before you buy.

Sources

• The Standard: future of the dtac brand after the three-year period (in Thai)
• Bangkok Post: True's one-network strategy completed, 30 October 2025
• True Corporation: amalgamation of dtac and True
• The Nation: NBTC measures on foreign and tourist SIMs
• NBTC: real-time liveness detection for SIM registration from 18 August 2025 (in Thai)
• True-dtac: tourist SIM terms
• AIS: where to buy the tourist SIM
• Koh Phangan Life: SIM and internet on Koh Phangan

Read also

• Travel eSIM guide: how it works
• eSIM or local SIM card
• How much data do you need for a trip
• Internet in Vietnam for tourists

FAQ

Do I need a passport for a SIM card in Thailand?

Yes. A Thai tourist SIM is registered to your original passport, and since August 2025 the counter also runs a live face check. A travel eSIM from Matrimix needs no passport or ID.

Is dtac still a separate operator?

No. dtac and TrueMove H are brands of True Corporation and now share one network. Both brands still sell SIMs at the time of writing, but the dtac brand's future is under review.

Does mobile internet work on the Thai islands?

On large islands such as Phuket and Koh Samui, usually well around towns and beaches. On small or remote islands, in national parks and on boat crossings, expect weak or no signal and download offline maps first.

Can I use one eSIM for Thailand and its neighbours?

Yes, if you choose a regional plan. Regional plans cover several countries, so check the list on the plan page before buying.