SIM Cards and eSIM in Thailand: The 2026 Complete Guide

Why Good Connectivity Matters in Thailand

Navigation, Grab rides, real-time translation, finding restaurants, booking ferries, staying in touch -- all of it requires a working data connection. Landing in Thailand without a SIM (or pre-configured eSIM) is an unnecessary inconvenience. Getting one takes less than 10 minutes and costs very little. This guide gives you the exact options, prices, and recommendations for 2025-2026.

Thailand's Carrier Landscape

A major event reshaped Thailand's telecom market in 2023: DTAC merged with TrueMove H, creating a combined entity operating under the True brand (True Corporation). This reduced Thailand's major carriers from three to two meaningful options:

AIS (Advanced Info Service)

Thailand's largest network by subscribers and by coverage. Strongest in urban areas and along major highways. Excellent 4G LTE throughout Bangkok and major cities. 5G expanding rapidly in Bangkok CBD, Chiang Mai, Phuket, and Pattaya.

AIS strengths: Best urban coverage, reliable data speeds (regularly 50-150 Mbps 4G in Bangkok), good customer service infrastructure, easy to top up (AIS shops, 7-Eleven, online).

AIS weaknesses: Rural fringe areas can be weaker than TrueMove (now True).

True (TrueMove H) -- formerly DTAC/True merger

The merged True/DTAC network is now Thailand's second-largest carrier. The merger combined DTAC's rural strength with True's urban infrastructure -- the combined network has arguably the best rural and provincial coverage.

True strengths: Excellent coverage in secondary cities and rural areas, good prices on long-term plans, the merged DTAC towers give better reach outside cities.

True weaknesses: Customer service infrastructure not yet fully rationalized post-merger. Some service gaps during network integration (mostly resolved by 2026).

NT (National Telecom)

State-owned carrier, previously TOT + CAT. Smaller network, primarily government and enterprise focus. Not relevant for tourist SIMs.

Tourist SIM Options

Where to Buy

Airport counter (recommended): All three Thai international airports (Suvarnabhumi BKK, Don Mueang DMK, Phuket HKT, Chiang Mai CNX) have AIS and True SIM counters in the arrivals hall, before you exit to the taxi/transport area. Buy here immediately on landing -- you will want Grab and Google Maps working the moment you step outside.

Queue time: 5-15 minutes at peak times. You need your passport for registration (required by Thai law). The process: present passport, choose package, pay cash or card, SIM activated within 2-3 minutes.

In-city retail: AIS has its own branded shops (AIS Play shops and AIS telewiz) in every major city. True has TrueMove H shops. Both brands also sell through 7-Eleven, where SIM cards can be purchased and topped up (though staff may not speak English -- have the package name ready).

Convenience stores: 7-Eleven sells basic tourist SIMs for both AIS and True at the counter. Less variety of packages than a carrier shop, but functional. Useful for top-ups.

AIS Tourist SIM Packages (2025-2026 pricing)

AIS offers several tourist-oriented packages. Prices are stable but exact packages update quarterly -- confirm at the counter.

AIS SIM2Fly Tourist SIM:

• 8-day package: 299 THB -- 15 GB high speed, then throttled unlimited, voice calls included
• 15-day package: 399 THB -- 30 GB high speed + unlimited throttled + voice
• 30-day package: 599 THB -- unlimited data (with high-speed daily cap of 1.5 GB/day), voice calls included
• Tourist SIM + Airport Wi-Fi: Bundled packages available at BKK/DMK airports

AIS Traveler SIM (long-stay):

• 90-day package: 999 THB -- 30 GB high speed data + unlimited throttled, voice calls included
• Good for digital nomads on tourist/DTV visas

AIS speeds: 4G consistently delivers 30-100 Mbps in cities. The "high-speed" cap means full 4G speeds until the daily or total limit is hit, then drops to approximately 1-2 Mbps (still usable for messaging, maps, and standard browsing but slow for video).

True (TrueMove H) Tourist SIM Packages

True Tourist SIM:

• 8-day package: 299 THB -- 15 GB high speed + unlimited throttled + voice
• 15-day package: 399 THB -- 30 GB + unlimited throttled + voice
• 30-day package: 599 THB -- unlimited (1.5 GB/day high speed) + voice
• 30-day Unlimited: 899 THB -- higher daily cap (up to 30 GB high speed total), unlimited throttled, voice

True long-term plans:

• 3-month: 1,199 THB -- 30 GB high speed + unlimited throttled
• 6-month: 1,999 THB -- 50 GB high speed + unlimited throttled

True coverage note: Since the DTAC merger, True has improved its coverage significantly in areas like Chiang Rai, Ubon Ratchathani, and rural Isaan where DTAC had strong presence. For travelers doing Chiang Rai/Golden Triangle, the True network now covers this well.

eSIM Options

For travelers with eSIM-compatible phones (iPhone XS and later, most Android flagships from 2019 onward, most 2024+ mid-range phones), eSIM offers the advantage of buying and activating connectivity before you land in Thailand.

What is an eSIM

An eSIM (embedded SIM) is a digital SIM baked into your phone. You download a carrier profile via QR code and activate it without a physical SIM card. You can have both your home SIM and a Thai eSIM active simultaneously (dual SIM functionality -- calls on home SIM, data on Thai eSIM).

Airalo: The Market Leader for Travel eSIMs

Airalo is the dominant third-party eSIM marketplace. They resell data-only eSIM plans (no voice calls) from local carriers in 200+ countries.

Thailand eSIM plans on Airalo (2025-2026):

• 1 GB / 7 days: $4.50
• 3 GB / 30 days: $9.00
• 5 GB / 30 days: $13.00
• 10 GB / 30 days: $19.00
• 20 GB / 30 days: $33.00

Airalo pros:

• Buy before you travel, activate on the plane
• No physical SIM to manage
• Competitive pricing for shorter durations
• Good app interface

Airalo cons:

• Data-only (no voice calls or Thai phone number)
• Not cost-competitive for 30-day unlimited plans vs local SIM
• Network assignment varies (Airalo uses AIS or True depending on availability -- you cannot choose)

When Airalo makes sense: Short trips (under 2 weeks), travelers who want connectivity immediately on landing without a queue, travelers who need to keep their home SIM active for voice calls.

Carrier eSIMs (AIS and True)

Both AIS and True offer native eSIM options, primarily for their long-term plans or for travelers who have purchased packages online before arriving.

AIS eSIM: Available through the AIS Online Shop. The same tourist packages as physical SIM available as eSIM. Requires downloading a QR code and installing the profile. AIS customer support for eSIM is reasonable.

True eSIM: Available through True Online. Similar packages to physical SIM. Note: some older True plans have had issues with eSIM activation for foreign handsets -- check compatibility.

Activation: Buy online, receive QR code via email, scan QR code in your phone's eSIM settings to install. Can be done before travel. Activation (turning the plan on) can be set for your arrival date.

Regional eSIM Options

For travelers visiting multiple Southeast Asian countries, regional eSIM plans offer coverage across several countries on one plan:

Airalo Southeast Asia plans: Cover Thailand, Malaysia, Singapore, Indonesia, Vietnam, etc. Useful if you are doing a multi-country trip. Pricing is per-country more expensive than a Thailand-only plan but convenient for short stays in multiple countries.

Nomad eSIM (Southeast Asia): Similar regional coverage. 10 GB / 30 days across 8 countries: approximately $25.

Giga (Southeast Asia): Another option. Plans start at $15 for regional coverage.

When regional eSIMs make sense: Visiting 3+ countries in one trip where the simplicity of one plan outweighs the cost difference.

Long-Term and Monthly Plans

For nomads and long-stay visitors, the tourist packages become expensive over time. Monthly plans offer better value:

AIS Monthly Plans

Available at AIS shops. Require a SIM (eSIM or physical) already registered.

• Happy Tourist (post-paid setup): Not available to tourists without a work permit or Thai ID
• Prepaid top-up packages: Add monthly bundles to a tourist SIM. AIS's "Happy" prepaid top-up packages:
• 300 THB/month: 20 GB high speed + unlimited throttled
• 500 THB/month: 50 GB high speed + unlimited throttled
• 800 THB/month: 100 GB high speed + unlimited throttled

These can be added on top of an existing tourist SIM that has the correct profile. Staff at AIS shops can help -- show them your existing SIM and ask for a monthly data package (package raiduean in Thai).

True Monthly Plans

Similar structure. True shops (formerly DTAC True shops) in major cities can set up long-term prepaid packages on tourist SIMs.

• 300 THB/month: 20 GB high speed
• 499 THB/month: 50 GB high speed + unlimited throttled
• 799 THB/month: 100 GB high speed + unlimited throttled

Coverage Reality Check

Cities and Tourist Areas

In Bangkok, Chiang Mai, Phuket, Koh Samui, Pattaya, and all major tourist areas: both AIS and True deliver excellent 4G coverage. Speeds of 30-80 Mbps are routine. 5G available in Bangkok CBD on both networks.

Rural Areas and Mountains

Both AIS and True have weaknesses in remote mountainous areas (far northern provinces, deep forest national parks). Doi Inthanon summit has spotty coverage on all carriers. Mae Hong Son and Pai have acceptable (if slower) 4G.

Golden Triangle border area (Chiang Rai province): Adequate True coverage, slightly weaker AIS. For border crossings to Myanmar or Laos, your Thai SIM coverage drops at the border -- international roaming kicks in or you have no signal.

Islands

Well-covered islands: Koh Samui (excellent both carriers), Koh Phangan (good, slightly weaker inland), Koh Tao (good at beaches, weak in interior), Koh Lanta (good on west coast), Koh Chang (good on west coast).

Islands with limited coverage: Koh Lipe (True better than AIS), Koh Kood (patchy), Koh Yao Noi (moderate), smaller uninhabited or lightly developed islands (assume no coverage).

Island wifi reality: Many beach guesthouses on smaller islands have fiber or satellite wifi for their premises, but 4G coverage for mobile may be weak between properties. Test mobile data before relying on it for work.

Topping Up

All tourist SIMs can be topped up (adding more credit or data) through:

• 7-Eleven: Cashier can top up AIS or True SIMs. Tell them the number and amount. Pay cash.
• AIS/True apps: Top up by credit card directly in the carrier apps
• AIS/True shops: In-person top-up
• Online: Both carriers have online top-up portals accepting international Visa/Mastercard

For adding data packages (not just credit), the carrier apps are the most convenient method -- they show your current balance and available packages in English.

Wifi and VPN

Free wifi availability: Most Thai hotels, hostels, cafes, malls, and coworking spaces have free wifi. Speed and reliability vary widely. Street-level wifi from local municipalities exists in some cities (Phuket, Chiang Mai areas) but is unreliable.

VPN usage: A significant number of streaming services geo-restrict content in Thailand (Netflix Thailand has a smaller library than Netflix USA, for example). A VPN is standard for most long-stay travelers:

• ExpressVPN: approximately $6-8/month
• NordVPN: approximately $4-6/month
• Mullvad: flat $5/month with no accounts required

Technical note: Thailand does not currently block VPN services themselves (as of 2026), though this can change. Major VPN providers work reliably from Thailand.

Quick Decision Guide

Short stay (under 14 days), any phone: Buy a physical tourist SIM at the airport. AIS or True, 299-399 THB, done in 5 minutes. No pre-planning needed.

Short stay, eSIM phone, want connectivity before landing: Buy Airalo Thailand eSIM before travel. Activate on the plane.

Medium stay (1-3 months), physical SIM: Buy 30-day tourist SIM (599 THB), add monthly top-up packages as needed.

Long stay (3+ months), digital nomad: Buy a proper monthly plan from an AIS or True shop in your city. 300-800 THB/month for adequate data. Pair with good home wifi or coworking space fiber for work.

Multi-country travel: Airalo Southeast Asia regional plan or Nomad eSIM if visiting 3+ countries. Otherwise, buy a local SIM in each country.

For overall connectivity as a digital nomad, see the digital nomad guide.