Short answer
You need your passport to buy a SIM card in Thailand, because every SIM must be registered under rules of the telecoms regulator, the NBTC. AIS, one of the main operators, lists tourist SIMs from 49 baht for one day to 1,599 baht for 60 days, and offers several as eSIMs. Guides say a local prepaid SIM from a convenience store costs less than an airport tourist SIM, at roughly 200 to 700 baht for 30 days. Registered numbers must be activated within 60 days.
Your passport is needed to buy a SIM
AIS's tourist SIM page tells buyers to register the SIM card before use in Thailand, in line with the rules of the National Broadcasting and Telecommunications Commission (NBTC). Wikivoyage's Thailand page and Lonely Planet say the same in practice: you must show your passport when you buy a SIM. So have the passport in your hand, not in the hotel safe, when you go to the counter or shop.
Registration is not the same as the Thailand Digital Arrival Card, which you file online before landing. The Immigration Bureau's FAQ says that travellers without a smartphone or internet can use kiosks and Wi-Fi after landing, at five airports: Suvarnabhumi, Don Mueang, Phuket, Chiang Mai and Hat Yai. Our guide to the arrival card explains the form.
Airport counter or convenience store?
Wikivoyage says the carrier counters at Bangkok's airport can register your passport and switch on service at any hour, in English, but sell only special tourist SIMs that it calls overpriced. Lonely Planet confirms that AIS, True and DTAC all have a presence at the airport kiosks, and adds that tourist SIMs bought at 7-Eleven are generally cheaper than at the airport. A credit-card payment there has a 200-baht minimum, it says.
The Longest Way Home's guide to Suvarnabhumi, updated on 18 February 2026, lists tourist SIMs at the airport counters of AIS, DTAC, True Move and NTNT at around 299 to 599 baht, depending on data and validity. Wikivoyage reports that in November 2025 a local SIM at 7-Eleven, with 30 GB of data for 30 days, cost 199 baht for DTAC and True. These are guide figures, not price lists, so check the price on the shelf. The shop's registration system only works in the daytime, usually until about 9 pm, Wikivoyage warns.
What AIS lists for tourists
AIS publishes the prices of its tourist SIM on its own site. A one-day SIM costs 49 baht and includes 1 GB of data. The longer plans give unlimited data on 5G and 4G: 399 baht for 5 days, 499 baht for 8 days, 699 baht for 15 days, 1,199 baht for 30 days and 1,599 baht for 60 days. The unlimited plans add free calls within the AIS network and a 100-baht call bonus, and social apps are data-free on all of them.
The page shows a "Buy eSIM" button on every plan except the 60-day one. These plans are simple and carry unlimited data, but the 30-day price is far above the 199-baht local SIM with 30 GB that Wikivoyage quotes. If you only need a few gigabytes for maps and messages, a cheaper local plan may be enough. Ask what the data allowance is before you pay.
eSIM: buy before you land
Lonely Planet says an eSIM is even more user-friendly than a physical card: choose a provider and plan, buy it, scan the QR code and follow the phone's instructions. Set it up before you arrive so that data works when you land. It also does not require you to take out your home SIM, so you can still receive calls and messages on your own number. Check that your phone supports eSIM.
Wikivoyage notes that DTAC offers a tourist eSIM and that True tourist eSIMs are available through a reseller, while AIS sells its own through its site. If you cannot get an eSIM working, a physical SIM at the airport is the fallback, and the counter staff register your passport and activate the service, according to Wikivoyage.
The 60-day rule and top-ups
AIS's tourist page quotes the NBTC rules: a number registered in a person's name must be activated within 60 days of registration, otherwise the identity check has to be repeated. A foreign tourist who wants to keep using a tourist SIM beyond 60 days from activation must confirm identity again, by sending the passport number by SMS to 4444161 (free of charge) or by visiting an AIS shop.
Wikivoyage adds that long-validity SIMs have largely been phased out, and that each top-up, large or small, now extends a SIM's validity by 30 days, up to a maximum of 365 days from the day of the top-up. This matters only if you plan to return within a year. For one trip of a week or two, a plan that covers your dates is enough.
Coverage on islands, boats and in parks
Lonely Planet says Thailand has 3G to 5G coverage in 95% of the country and that AIS and True hold most of the market. It also warns that rain can hurt connectivity, and that remote areas, including some national parks, can be affected; AIS is said to work better in regions such as the north-east. Wikivoyage says AIS generally has the best network in the countryside but is slightly more expensive.
Do not count on a signal at sea or on remote beaches, so download maps beforehand. On our Phi Phi and Maya Bay speedboat tour the pickup time is confirmed the day before, and we send it on WhatsApp, so check your messages that evening. The tour is from $75 per person, and a dry bag keeps the phone safe on the boat.
Other times you may need a Thai number
The Tourism Authority of Thailand says a Thai SIM card is required to start drone registration through the Civil Aviation Authority's portal, which verifies identity with a one-time password. See our drone rules guide for what else is involved. Taxi apps also work best with data, so a plan helps if you use the ones in our Grab and Bolt guide.
Roaming is the other option. Wikivoyage says roaming onto Thailand's networks is possible, subject to agreements between operators, and Lonely Planet says a local SIM lets you avoid international roaming charges. Check your home plan's roaming price per day before you decide. For public Wi-Fi, Lonely Planet says to avoid checking bank accounts on public networks.
Practical checklist
- Keep your passport in your hand luggage, because you need it to buy and register a SIM.
- Decide before you fly: an eSIM bought in advance, or a physical SIM at the airport counter.
- Compare the airport price with a convenience-store SIM, and ask what the data allowance is.
- Activate the number within 60 days of registration, and top up if you stay longer.
- Download offline maps before a boat day, and keep your phone in a dry bag.
Questions and answers
Do you need your passport to buy a SIM card in Thailand?
Yes. AIS tells buyers to register the SIM before use under NBTC rules, and Wikivoyage and Lonely Planet both say you must show your passport when you buy one.
How much is a tourist SIM card in Thailand?
AIS lists 49 baht for one day with 1 GB, and unlimited-data plans of 399 baht for 5 days up to 1,599 baht for 60 days. Guides report cheaper local SIMs of roughly 200 to 700 baht for 30 days.
Can you buy a SIM card at Bangkok airport at night?
Wikivoyage says the carrier counters at Bangkok's airport can register your passport and activate service 24 hours a day, but sell only special tourist SIMs, which it calls overpriced.
Is an eSIM better than a physical SIM in Thailand?
Lonely Planet calls it more user-friendly: buy and set it up before you arrive, and keep your home SIM in the phone. It requires an eSIM-compatible phone, so check yours first.
How long does a Thai tourist SIM last?
AIS says a registered number must be activated within 60 days, and that a tourist SIM used beyond 60 days from activation needs identity confirmation again. Wikivoyage says each top-up extends validity by 30 days.