AIS vs DTAC vs TrueMove: Best SIM Card for Thailand Tourists

Pick up any tourist SIM guide for Thailand and you hit the same problem: AIS, DTAC and TrueMove H sell almost identical plans at almost identical prices. The real differences in 2026 are coverage, registration rules and how you activate the SIM. This guide shows you where those differences matter, so you can choose in a few minutes and spend the rest of your time on the trip.

AIS vs DTAC vs TrueMove H: What Each Network Does Best

Thailand’s mobile market is dominated by three providers: AIS (Advanced Info Service), DTAC (Total Access Communication) and TrueMove H. All three sell a tourist SIM with data, local calls and free access to their Wi-Fi hotspots. Each also bundles perks, such as free access to certain apps.

AIS Traveller SIM

AIS is generally seen as the market leader and is praised for its network reach, especially in remote areas. The Traveller SIM includes high-speed data, local calls, international calls (dial 003 or 00500 first) and free AIS Super WiFi. Some plans also include free social media app usage. Manage everything in the My AIS app. The tourist section is on www.ais.th.

DTAC Happy Tourist SIM

DTAC is the second-largest provider, known for competitive pricing and good urban coverage. The Happy Tourist SIM includes high-speed data, local calls, international calls (dial 004), free DTAC Wi-Fi, and often free access to messaging apps such as WhatsApp and LINE. Use the DTAC app for balance checks and top-ups. The tourist section is on www.dtac.co.th.

TrueMove H Tourist SIM

TrueMove H, now merged with DTAC, is known for a strong 5G presence in major cities. Its tourist SIM includes high-speed data, local calls, international calls (dial 006), free True Wi-Fi, and often free use of social apps such as Facebook, Instagram and TikTok. The app is True iService, and the tourist section is on www.truemoveh.truecorp.co.th.

A quick way to decide: heavy LINE or WhatsApp user, look at DTAC. Posting to Instagram and TikTok all day, look at TrueMove H. Heading to far-flung islands or parks, start with AIS.

Coverage Reality: Cities, Islands and National Parks

In Bangkok, Chiang Mai, Phuket, Pattaya and other urban centres, all three networks deliver excellent 4G and increasingly widespread 5G. Google Maps, Grab, video calls and streaming all work reliably. In these places the network you pick hardly matters.

Remote places are where the choice counts:

• AIS generally has the widest reach. It is the one to pick if you plan extensive travel to remote locations or smaller islands.
• DTAC and TrueMove H are strong in populated island areas such as the main towns of Koh Samui and Koh Phi Phi. They can get spotty or drop to 3G/2G in very remote parts of islands or national parks, such as certain beaches on Koh Lanta or parts of Khao Yai National Park.

2026 Budget Reality: What Tourist SIMs Cost in THB

The plans below are based on late 2024 and early 2025 offerings. Specific data allowances and prices are subject to change in 2026, so confirm at the counter or on the provider’s website. Right now the three providers list similar figures:

• Budget (8-day plan): typically 15GB of high-speed data, then unlimited data at 256 Kbps, plus 15 THB call credit. Approximately 299 THB.
• Mid-range (15-day plan): typically 30GB of high-speed data, then unlimited at 256 Kbps, plus 15 THB call credit. Approximately 499 THB.
• Comfortable (30-day plan): often 50GB of high-speed data, then unlimited at 256 Kbps, plus 15 THB call credit. Approximately 799 THB.

Since prices are this close, do not choose on price alone. Choose on coverage, perks and how easy activation is.

Count your days honestly. A 10-day trip means the 15-day plan, which at about 499 THB is still far cheaper than roaming charges from most home carriers.

Buying a Physical SIM Step by Step

You can buy a tourist SIM at the major international airports (Suvarnabhumi BKK, Don Mueang DMK, Phuket HKT and Chiang Mai CNX), at official provider stores in shopping malls, and at convenience stores like 7-Eleven and FamilyMart. Airport kiosks often have dedicated staff to help with activation.

1. Check your phone is unlocked. A locked phone will not accept a Thai SIM.
2. Bring your passport. It is mandatory for registration.
3. Choose your plan (8, 15 or 30 days).
4. Complete biometric registration. This means a passport scan plus a fingerprint or facial recognition scan at the point of purchase. It usually takes 1 to 3 minutes after you select a plan.
5. Let staff install the SIM and test that data works before you walk away.

Setting Up an eSIM Before You Land

All three providers offer eSIM for tourists. It removes the need to swap physical cards, and you can often buy and activate it before arriving in Thailand. You can buy online from the provider’s website, at airport counters or official stores, or from a reputable reseller.

1. Make sure your phone is eSIM compatible and unlocked.
2. Buy an eSIM package online. A QR code arrives by email.
3. On iPhone, go to Settings > Cellular/Mobile Data > Add Data Plan. On Android, go to Network & Internet > Mobile Network > Download a SIM.
4. Scan the QR code.
5. Follow the on-screen prompts. You may need an internet connection, such as airport Wi-Fi, to download the eSIM profile.

In-store, staff help with the QR code download after registration.

Advantages: no physical card to lose, you can keep your home SIM active for SMS such as banking OTPs, and switching plans is easier. Disadvantages: you need an eSIM-compatible device, and the first activation needs internet access.

Wi-Fi in Thailand: When You Don’t Need Data

Free Wi-Fi is widely available in most cafes, restaurants and eateries, particularly in tourist areas. The password is usually displayed on the wall or provided when you ask. Hotels, guesthouses and hostels almost universally offer free Wi-Fi to guests, typically with good speeds.

Public Wi-Fi in open spaces is less common than in private businesses. Some providers, such as AIS Super WiFi and True Wi-Fi, run extensive hotspot networks, often included free with their tourist SIM packages, and these are generally secure.

Topping Up, Checking Balance and Emergency Numbers

Top-ups: You can add data or call credit at 7-Eleven or FamilyMart by giving your phone number. You can also use the provider app (My AIS, DTAC app or True iService) with a credit or debit card, or visit an official store.

Balance checks: Use the provider’s app, or try the USSD codes: *121# for AIS, *101# for DTAC and *123# for TrueMove H. If a code does not work, use the app instead, since codes can change.

Emergency numbers:

• Police: 191
• Tourist Police: 1155
• Ambulance and medical emergency: 1669

Useful apps: Download Grab or Bolt for ride-hailing. For inter-city trains, use the State Railway of Thailand (SRT) website or app for schedules and tickets.

What Changed Since 2024

• Mandatory biometric registration. This is the biggest change for tourists. A fingerprint or facial scan, alongside passport verification, became strictly enforced across all sales channels (airports, convenience stores, official shops) around late 2023 or early 2024. It is meant to improve security and prevent misuse.
• More eSIM options. eSIMs are now more readily available and streamlined across all three major providers, making them a more viable choice.
• The True-DTAC merger. The tourist SIM brands remain distinct, but network integration between TrueMove H and DTAC is gradually producing a more unified network. The benefit should be more consistent coverage, especially in less populated areas where one network was weaker.
• More data for similar prices. Tourist plans have generally seen higher high-speed data allowances at similar price points, and older, less generous plans are phased out. As of late 2024, no major popular tourist SIM options had been entirely discontinued.
• 5G expansion. AIS continues to invest heavily in 5G, and TrueMove H has continued to expand its 5G network aggressively.

Common Mistakes to Avoid

• Arriving with a locked phone. Check with your home carrier before you leave. A locked phone will not accept a Thai SIM.
• Forgetting your passport. Registration cannot be done without it, even at a convenience store.
• Choosing by price only. The three networks cost about the same. Pick based on where you are going, and lean toward AIS for remote islands and parks.
• Waiting for an eSIM download on weak signal. You need an internet connection for the profile. Use Wi-Fi.
• Removing your home SIM and losing OTP codes. Keep it active via eSIM or a dual-SIM setup if your bank texts you codes.
• Ignoring the 256 Kbps drop. After you use your high-speed quota, speeds fall to 256 Kbps. That is enough for messages but poor for maps and video. Track usage in the app.
• Assuming prices are fixed. Plans change often. Confirm the current data and THB price before paying.

Frequently Asked Questions

Which SIM is best for tourists in Thailand in 2026?

AIS is the safest choice if you will visit remote islands or national parks, because it generally has the widest reach. For cities only, all three give excellent 4G and growing 5G at similar prices. Choose by itinerary: AIS for remote areas, DTAC for messaging apps, TrueMove H for city 5G.

Do I need my passport to buy a SIM card in Thailand?

Yes. A valid passport is mandatory. Registration also requires biometric verification, meaning a fingerprint or facial recognition scan at the point of purchase. This applies at airports, convenience stores and official shops. It usually takes 1 to 3 minutes after you choose a plan, and your phone must be unlocked.

Can I use an eSIM in Thailand as a tourist?

Yes. AIS, DTAC and TrueMove H all offer eSIM for tourists. Buy online, receive a QR code by email, then scan it in your phone settings. You need an eSIM-compatible, unlocked phone and an internet connection, such as Wi-Fi, to download the profile.

How do I top up my Thai SIM?

The easiest way is at 7-Eleven or FamilyMart: give the cashier your phone number and pay. You can also top up in the My AIS, DTAC or True iService app with a credit or debit card, or at an official provider store.

Is free Wi-Fi enough, or do I need a SIM?

Free Wi-Fi is common in cafes, restaurants and almost all accommodation, but public Wi-Fi in open spaces is less common. For maps, Grab rides and translation while moving around, you need mobile data. A tourist SIM from about 299 THB covers that for 8 days.

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📷 Featured image by Patrick Schöpflin on Unsplash.