Staying connected in Thailand is easy and genuinely cheap — a local SIM card typically costs 90% less than international roaming for equivalent data. Land in Bangkok, Phuket or Chiang Mai and you can have a working Thai number and fast 4G data in under 30 minutes. This guide covers every option honestly: physical SIM cards, eSIMs you can set up before you leave India, dual-SIM tricks so your home number stays reachable, and the few things that can go wrong.
One thing worth saying upfront: Thailand's three main networks — AIS, TrueMove H, and DTAC — all offer solid coverage across cities, beaches, and the major tourist corridors. The differences between them matter less than choosing the right validity and data plan for your trip length.
Physical SIM Cards: What to Buy at the Airport
Every major Thai airport — Suvarnabhumi (Bangkok), Don Mueang, Phuket, and Chiang Mai — has official counters from AIS, TrueMove H, and DTAC in the arrivals hall, open 24 hours. You can walk out connected. One note: some sources report airport pricing is slightly higher than city shops, so if you are arriving at a relaxed hour, you can also pick up a SIM from any 7-Eleven or operator store in town.
You must present your physical passport — photocopies are not accepted. Registration takes around 10–30 minutes and includes filling a short form. Staff at major airport counters speak English.
AIS
Best all-round pick, with the widest nationwide 4G/5G coverage, reliable in rural areas and islands. Popular plans include an 8-day / 15 GB plan at 299 THB (around ₹720) and a 30-day / 50 GB plan at 899 THB (around ₹2,160). Unlimited data plans with fair-use throttling after daily limits cost around 399–999 THB depending on validity.
TrueMove H
Strong 5G speeds in Bangkok and resort cities, with free access to True Wi-Fi hotspots. The 8-day unlimited plan is 449 THB and the 30-day unlimited plan is 1,199 THB. Includes 100 THB international call credit and unlimited local calls. Good choice if you will spend most of your time in cities.
DTAC (now merged with TrueMove H)
Matching price structure to TrueMove H, with a useful bonus: the Happy Tourist SIM includes 30 minutes of international calls to India — handy for a quick call home without eating into your data. Plans start at 449 THB for 8 days.
eSIM: Set It Up Before You Board
If your phone supports eSIM (most phones sold after 2020 do — check Settings to confirm), this is the slickest option for Indian travellers. You buy a QR code online, install the eSIM on your device before departure, and activate it the moment you land. No airport queue, no fumbling with a SIM pin.
The practical advantage for dual-SIM phones: your Indian SIM stays in the physical slot, so family can still reach you on your Indian number and WhatsApp notifications from your home number continue normally. The eSIM handles Thai data in the background.
Popular eSIM providers for Thailand:
- Airalo — runs on the AIS network; fixed-data plans from around $4–$24 USD. Good value for light to moderate use.
- Holafly — unlimited data plans on TrueMove H; priced roughly $3.90 per day or around $30 for two weeks. Useful if you watch a lot of video.
- Nomad — competitive on large bundles; 50 GB plans around $12 USD.
Set up the eSIM profile at least a day before you travel — do not leave it for the airport Wi-Fi.
How Much Data Do You Actually Need?
For most travellers on a 7–14 day trip, 15–30 GB is more than enough for Google Maps, WhatsApp video calls, Instagram, and streaming the occasional show at the hotel. Heavy video streamers or remote workers should look at unlimited plans with fair-use policies.
- Light use (maps, messaging, occasional Google): 8 GB is fine for a week
- Moderate use (social media, WhatsApp video, YouTube): 15–20 GB for two weeks
- Heavy use (remote work, constant video calls, hotspot for a laptop): Go unlimited — AIS or TrueMove H 30-day plans are worth it
All providers apply a fair-use policy on unlimited plans — typically around 2–2.5 GB at full speed per day before throttling to 1–4 Mbps. That speed is still fine for calls and messaging, just slower for video.
Tips Specifically for Indian Travellers
Buy a SIM in India before you go. Services like TSIM (tsim.in) sell pre-registered Thailand SIM cards that ship to Indian addresses. This saves airport time and means you land already connected — useful if you need to contact your hotel or transfer driver immediately on arrival.
Keep your Indian SIM active. Most Indian phones are dual-SIM. Leave your Jio/Airtel/Vi SIM in slot one and put the Thai SIM or eSIM in slot two. Your Indian number stays reachable, banking OTPs arrive normally, and WhatsApp on your Indian number keeps working. Simply turn off data roaming on the Indian SIM so you are not accidentally charged.
DTAC international call bonus. The DTAC Happy Tourist SIM includes 30 minutes of free calls to India, which covers a quick "landed safely" call home without touching your data balance.
INR-to-THB for quick budgeting. At the time of writing, 1 THB is roughly ₹2.9, so a 299 THB SIM costs around ₹870 and a 1,199 THB plan costs around ₹3,480. Exchange rates shift, so check a live converter before you travel.
Booking activities via WhatsApp. Trip Dust accepts bookings directly on WhatsApp (+66 82 885 5990), so having a working number from the moment you land means you can confirm activities, ask questions, and reach us if plans change — which, in Thailand, they often do.
Coverage by Region
Thailand's tourist belt is well covered by all three main operators, but a few things are worth knowing:
- Bangkok: Excellent 5G and 4G from all providers. TrueMove H and AIS are fastest in the city.
- Pattaya: Full 4G/5G coverage; AIS and TrueMove H perform well. Signal is strong across Coral Island boat routes too.
- Phuket: Good coverage on the main island including Phi Phi Island ferry routes, though expect gaps in open sea.
- Krabi: Town and main beaches well covered; outer islands like the Railay peninsula have patchier signal.
- Chiang Mai: City and popular trekking areas well covered; remote hill tribe routes may have gaps — download offline maps before heading out.
AIS has the strongest rural and island coverage overall if you are travelling off the standard tourist trail.
What If Your Phone Is Locked?
Some phones purchased on contract in India are network-locked and will not accept a foreign SIM. Check before you travel: insert a different Indian SIM (not your own network) and see if it works. If the phone is locked, your options are:
- Contact your Indian carrier to request an unlock code (often free after 90 days of contract)
- Use an eSIM if your phone supports it — eSIMs bypass the physical SIM lock entirely on most devices
- Buy an inexpensive unlocked handset in Thailand — basic smartphones are available at MBK Center or IT City from around 2,000–3,000 THB
iPhones sold in India since 2023 are typically unlocked by default. Most recent Android flagships from Samsung, OnePlus, and Xiaomi sold in India are also unlocked.
Frequently asked questions
Can I buy a Thailand SIM card at the airport without a Thai phone number?
Yes — airport counters sell you a brand-new Thai number as part of the SIM package. You bring your passport, they register the SIM in your name, and you leave with an active Thai number. No existing Thai number is needed.
Will my Indian WhatsApp number still work if I use a Thai SIM?
Yes. WhatsApp is tied to your Indian phone number and SIM, not to which SIM is currently handling data. On a dual-SIM phone, keep your Indian SIM in slot one with data roaming turned off — WhatsApp will route through the Thai data SIM automatically. On a single-SIM phone, you can use WhatsApp Web on a computer, or transfer your Indian number to an eSIM before travel so both can coexist.
Is there a difference in price between buying a SIM at the airport versus in a city shop or 7-Eleven?
Prices are very similar — official AIS, TrueMove H, and DTAC counters at airports generally match or come close to city prices. Buying at the airport is convenient and staff speak English. If you are arriving at a busy time and the queues are long, you can also pick up a SIM at any 7-Eleven using a simple top-up process, though the initial tourist SIM registration requires an operator counter.
Do Thai SIM cards work on boats and islands?
Coverage on ferries and islands varies. Major routes — such as Bangkok to Pattaya, Phuket town to Phi Phi Island, or Krabi to Railay — have reasonable signal for most of the journey, though open-sea stretches will drop. On the islands themselves, the main beaches and towns are well covered. Download offline Google Maps for your destination before you head out to sea, just in case.
What is the cheapest way for an Indian traveller to stay connected in Thailand for a week?
The AIS 8-day / 15 GB plan at 299 THB (around ₹720) is hard to beat for a 7–10 day trip. For even lower spend, some eSIM providers offer plans under $5 USD for 5–7 days of moderate data. The key is to avoid international roaming on your Indian SIM — even a few minutes of accidental roaming can cost more than a full Thai SIM.
Can I use a Thai SIM to call Trip Dust or book activities?
Absolutely. Once your Thai SIM is active, you can WhatsApp Trip Dust directly on +66 82 885 5990 for instant responses on bookings, activity questions, or last-minute changes. WhatsApp calls and messages over a Thai data SIM are free, so there is no call cost to worry about.