To stay connected in Thailand, two options stand out: a tourist SIM card bought on arrival, or an eSIM installed on your phone before you even take off. A Thailand eSIM wins on convenience; a physical SIM wins with a Thai number and unlimited data at local prices. Mr Schaka compares the two: operators, prices, passport registration, phone compatibility, coverage on the islands, calls and the apps worth installing.
Thai mobile operators in 2026: AIS and True-dtac
Thailand’s mobile market now has two main players. AIS is the country’s largest operator and is often praised for its coverage outside the cities. True and dtac merged in 2023 under True Corporation, and their two networks were fully combined at the end of 2025. The TrueMove H (or simply True) and dtac names still appear on SIM cards and in “True dtac Shop” stores, but they now run on the same network.
In practice, both AIS and True-dtac cover Bangkok, Chiang Mai, Phuket and the main tourist areas very well. The difference shows mostly in remote places, more on that below.
The tourist SIM at the airport: prices, passport, registration
AIS and True-dtac counters are in the arrivals hall at Suvarnabhumi and Don Mueang, after baggage claim. You will also find them at the airports in Phuket, Chiang Mai and Koh Samui. Staff insert the card, register it and activate it on the spot.
Prices checked in 2026 (check again before you travel, offers change often):
- AIS: about 299 THB (around €8 / $9) for 8 days with 15 GB of data;
- True (Tourist Infinite): 449 THB (around €12 / $14) for 8 days of unlimited 5G/4G data, with free local calls capped at 15 minutes per call;
- 30-day unlimited plans: around 1,199 THB (about €32 / $37) at the airport counter.
“Unlimited” data comes with a fair-use policy: past a certain volume, speeds may drop. In town, at operator stores or shopping malls, plans are sometimes a little cheaper than at the airport.
Your passport is mandatory: every number must be registered to its user. Since August 2025, operators must also check identity with a live facial scan when registering a new SIM. A foreigner can register a maximum of three SIMs per operator. Allow a few minutes at the counter, longer when several big flights land at once.
Good to know: tourist plans last no more than 60 days. For a long stay, ask a store for a regular prepaid plan, again with your passport. Registration rules change: check before you travel.
Thailand eSIM: international or Thai operator?
An eSIM is a virtual SIM card. You buy it online, receive a QR code by email and scan it in your phone’s settings. There are two kinds.
- International eSIM (Airalo, Ubigi, Holafly, Saily…): bought before you leave, it roams on a Thai network. No counter, no queue, online as soon as you land. It usually gives data only, without a Thai number. Small plans start at a few dollars for 1 GB; unlimited costs much more.
- Thai operator eSIM: AIS and True-dtac also sell their tourist plans as eSIMs, through their online stores, resellers or at the counter. You keep local prices and, depending on the offer, a Thai number. Passport registration still applies.
The choice is then simple. For a short trip, if you don’t want to queue on arrival, an international eSIM is the most comfortable. For two weeks or more, with lots of data and a need for a local number, a Thai operator SIM or eSIM usually works out cheaper.
Is your phone compatible?
For an eSIM, you need a compatible, unlocked phone, meaning one not locked to your home carrier. Apple supports eSIM from the iPhone XS and XR onwards. On Android, most recent Samsung Galaxy and Google Pixel phones support it, but not every entry-level model. Check your settings (the “Add eSIM” menu) or the manufacturer before buying. For a physical SIM, the phone simply needs to be unlocked and have a SIM tray.
A big plus of the eSIM: your usual SIM stays in the phone. You keep receiving text messages from your bank, often needed to confirm a payment. Remember to turn off data roaming on your home line to avoid a nasty bill.
Good to know: install the eSIM at home on a good Wi-Fi connection, and check when your plan starts counting days. Keep the QR code safe: with many offers, it can only be installed once.
Coverage on the islands and in remote areas
Bangkok, Phuket, Krabi, Koh Samui and the main tourist beaches have good 4G coverage, often 5G. On smaller islands the signal becomes patchy. On Koh Tao it is fine at Sairee and Mae Haad, weaker on the east coast. Koh Lipe remains poorly served, and some small islands around Koh Chang have almost no signal. In the northern mountains and national parks, AIS is often considered more reliable. Before heading to these places, download your maps and tickets.
Calls, WhatsApp and Wi-Fi
Once you are connected, WhatsApp, LINE and other messaging apps work normally, video calls included. LINE is the most widely used messaging app in Thailand: hotels, guides and shops often offer it. A Thai number is still handy when a driver, a delivery rider or a restaurant needs to reach you, and full tourist plans include local calls. “Data-only” plans do not allow outgoing calls, except to emergency numbers.
Free Wi-Fi is everywhere in hotels, cafés, shopping malls and airports. It helps, but it does not replace mobile data for getting around. On a public network, avoid banking.
Apps to install before you go
- Grab: private cars, taxis, motorbike taxis and food delivery, with the price shown upfront;
- Bolt: an often cheaper alternative in Bangkok and the big cities;
- Google Maps: routes on foot, by BTS, MRT and boat; download the offline map;
- Google Translate: download Thai for offline use and use the camera for menus and signs;
- LINE: to chat with Thai people and many hotels.
For your first ride, everything is explained in our guide to arriving in Bangkok from the airport. After that, see how to get around Bangkok by BTS, MRT and boat, and keep our Thai phrasebook handy when translation isn’t enough.
Mr Schaka’s free app: to find your way around Bangkok, install Thaïlande en poche. It is free, installs directly from the website and brings together the maps and addresses from the guide.
Frequently asked questions
Can I buy a Thai SIM card without a passport?
No. A passport is required to register any new SIM, along with a face check. Only an international eSIM, which works on roaming, can be bought online without visiting a counter.
Does an eSIM work as soon as I land?
Yes, if you installed it before leaving: just switch on the eSIM line and data roaming when you get off the plane. Handy for booking a Grab without hunting for Wi-Fi.
Which option is best for two weeks?
If you use a lot of data or want a local number, an AIS or True-dtac tourist SIM or eSIM is usually the cheapest. For light use, an international eSIM with a few GB is enough.
Can I keep my usual number?
Yes, with a dual-SIM or eSIM-compatible phone. Keep your home line active for text messages, but turn off its data roaming.
Want to dig deeper?
Airport, transport, neighbourhoods, addresses: Mr Schaka’s Bangkok – The Practical Guide gathers everything you need to plan your stay and find your way around the Thai capital with ease. The English edition is out now as a PDF ebook: buy it here →
