Staying connected in Thailand is easy and cheap compared with many countries. You can pick up a tourist SIM at the airport, install an eSIM before you land, or use roaming from your home plan. Each option makes sense for different trips. This guide explains the differences, compares the three main mobile operators in a neutral way, and lists the practical points that trip people up. Prices and plan details change frequently, so check the current price and terms on the operator's own page. Figures are approximate, as of 2026. This page does not recommend a specific paid provider.
The three options at a glance
| Option | Typical cost (approx.) | Setup | Phone number | Best for |
|---|---|---|---|---|
| Airport or shop tourist SIM | THB 300-700 for a 7-15 day data pack | Buy in person; passport registration; staff install it | Thai number, often with calls included in some packs | Travellers who want help on arrival |
| eSIM (operator or third-party marketplace) | THB 200-800 depending on data and days | Install by QR or app, before or after landing | Often data-only | Dual-SIM phones, short stays, no queue |
| Roaming on your home plan | Varies widely, from included to expensive per day | None | Your own number | Short trips or when your plan includes Thailand |
If you only need maps, ride-hailing and messaging for a week, an eSIM is usually the lowest-friction choice. If you want a local number for deliveries, banking apps or booking confirmations, a physical SIM with a Thai number is better.
Physical tourist SIMs
All three major networks sell tourist SIM packs at airport counters (such as at Suvarnabhumi, Don Mueang, Phuket and Chiang Mai), and in their stores and convenience-store-linked kiosks in town. Typical pack features:
- A fixed amount of data for a stated number of days, sometimes with a speed throttle after a high-speed allowance.
- Optional bundled call credit.
- Passport registration by the shop, as required by Thai regulation, so bring your passport.
Airport counters are convenient, but prices there can be slightly higher than in shops in town. Compare a couple of counters before paying. After the pack expires you can often top up with a Thai number via an app or shop.
eSIMs
An eSIM is a digital SIM installed on your phone by QR code or app. Your phone must be eSIM-capable and unlocked (not tied to a carrier). Options include:
- Operator eSIMs: AIS, True and some others offer tourist eSIMs, sometimes purchasable online before arrival or at the airport.
- Marketplace and travel eSIMs: third-party sellers offer regional and Thailand-specific data plans. Quality varies, and they typically resell capacity on one of the Thai networks, so check which network it uses and whether you get local or roaming-style speeds.
Practical points:
- Install the eSIM while you have Wi-Fi, ideally before you fly, then enable it on arrival.
- Keep your home SIM active as secondary if you want to receive texts for bank verification.
- eSIMs are usually data-only; you can still call and message using WhatsApp, LINE and similar apps.
- Check if the plan is a fixed-day pass or a pay-per-GB plan, and whether unused data expires.
- Keep the QR code until the end of the trip; some phones need reinstalling if you reset.
Roaming
Some home carriers offer day passes or include Thailand in regional bundles. Roaming is simple and keeps your number, but uncapped or default rates can be very expensive. Read your carrier's current price list before you travel, and disable data roaming if you do not have a plan. If your trip is longer than a few days, a local SIM or eSIM is usually cheaper, though comparing prices is the only way to be sure.
Thailand's mobile operators
Thailand has two large networks following the merger of True and dtac in 2023, plus smaller or government-linked operators. The brands may still be sold separately.
| Operator | Reputation (stated criterion: coverage claims and broad market position) | Tourist products | Notes |
|---|---|---|---|
| AIS | Largest operator by subscribers in recent years | Tourist SIM and eSIM packs, airport counters | Often cited for rural coverage; confirm on the operator's map |
| True (including dtac brand) | Second major group; dtac customers are being integrated | Tourist SIM packs sold under True and dtac names | Strong in cities; confirm coverage on the islands you are visiting |
| Smaller operators | Limited | Few tourist-targeted products | Rarely needed by visitors |
Coverage differs by area, island and even valley. Operators publish coverage maps on their sites; check them for remote places such as national parks, northern mountain routes and small islands before choosing. No single network is best everywhere.
Speed and technology
Major cities and tourist areas generally have 4G and 5G coverage on the main networks, as described by the operators. Speeds vary with crowd and location. The Thai regulator, the NBTC, oversees spectrum and telecom rules. Some phones that only support older bands may not get the best speeds.
What to check before you buy
- Phone compatibility. Is it unlocked, and does it support eSIM if you want one? Check the manufacturer's settings or support page.
- Days and data. Match the validity period to your stay, not to your arrival date.
- Network. For an eSIM from a marketplace, check which Thai network it uses.
- Hotspot. Some plans restrict tethering; check if you need to share data with a laptop.
- Calls and number. Do you need local calls, for example to restaurants or guesthouses?
- Top-up. Can you extend it later through an app or a shop?
- Refund policy. Marketplace eSIMs often cannot be refunded once installed.
Airport tips
- Landing to SIM: counters in arrival halls are well signposted; allow 10-20 minutes in busy periods.
- Wi-Fi first: if you install an eSIM, do it before leaving the airport so you can summon a ride and open your TDAC confirmation. See Thailand entry requirements and TDAC.
- Do not hand over your passport to unofficial sellers. Use official counters or stores.
- Keep your receipt and note the support number or app instructions for activation problems.
Using your connection
- Maps and ride-hailing: Grab, Bolt and Google-style map apps use modest data. See getting around Thailand.
- Messaging: LINE is dominant locally, along with WhatsApp and Facebook Messenger.
- Translation: offline language packs reduce data use.
- Scams and security: avoid public Wi-Fi for banking, and use a VPN if you like. See safety, scams and health.
For airport transport in the capital see Bangkok airport to city, and for budgets see Thailand budget per day.
FAQ
Is eSIM better than a physical SIM in Thailand?
It is more convenient if your phone supports it, because you can set it up before landing. A physical SIM gives you a Thai number and in-person help. The better choice depends on your phone and your needs.
Do I need my passport to buy a SIM?
Yes. Thai regulations require registration with a valid ID, and for visitors that means the passport. The shop or the app handles the registration process.
Which network has the best coverage?
AIS and True both have wide national coverage, and which one is stronger varies by location. Check the operators' coverage maps for the places you plan to go, especially remote areas and small islands.
Can I keep my home number active?
If you have a dual-SIM phone with eSIM, you can keep your home SIM and use the Thai eSIM for data. Make sure your home plan will not charge roaming data by switching it off.
What happens if my eSIM does not activate?
Check that data roaming is enabled for the eSIM line, restart the phone and confirm that the plan has started. Contact the seller's support if it still fails. Having a backup option, such as airport Wi-Fi, is useful.
How much data do I need?
Maps, messaging and occasional social media typically use 1-2 GB for a week, while video and hotspot use consume much more. Choose a plan with a margin or an easy top-up.
Official sources and further reading
Prices, schedules and entry rules change. Figures here are approximate as of 2026; always confirm on the official or operator page before you book. Spotted something out of date? Tell us.
