Thailand SIM Cards & Internet Guide: Best Plans, eSIMs, and Home Internet

Thai Mobile Carriers Compared (AIS, TrueMove, DTAC)

Thailand has three major mobile carriers: AIS (Advanced Info Service), TrueMove H (True Corporation), and DTAC (Total Access Communication, now part of True Corporation after a 2022 merger). All three provide nationwide 4G coverage with growing 5G networks in major cities.

AIS is Thailand's largest mobile operator with approximately 45 million subscribers. AIS has the best nationwide coverage, particularly in rural and remote areas. If you plan to travel to islands, national parks, or less-visited provinces, AIS is the safest choice for consistent coverage. Their 5G network is expanding rapidly in Bangkok, Chiang Mai, and other major cities. AIS also operates AIS Fibre for home internet. Customer service is available in English through their call center (1175). AIS prepaid plans are competitively priced, with monthly packages starting at 200 THB.

TrueMove H is the second-largest carrier and excels in urban coverage and speed. True's 5G network in Bangkok is arguably the fastest among the three carriers. TrueMove H is ideal if you spend most of your time in Bangkok, Chiang Mai, Phuket, or other major cities. The advantage of True is bundling: if you also have True Online home internet or TrueVisions TV, you can get significant discounts by combining services. TrueMove's call center (1242) has English-speaking agents. Prepaid plans start at 200 THB per month.

DTAC, now merged with True Corporation, continues to operate as a separate brand. DTAC offers competitive pricing and good coverage in urban areas. Their network shares infrastructure with TrueMove, which has improved coverage in some areas. DTAC is known for straightforward pricing and good promotional offers. Their call center (1678) provides English support. Prepaid plans start at 199 THB per month.

Coverage comparison: In Bangkok, all three carriers perform similarly with excellent 4G and expanding 5G. In Chiang Mai, AIS and TrueMove have the best coverage. On islands, AIS generally has the strongest signal. In remote rural areas and national parks, AIS is the clear winner. For most expats, any of the three works fine for daily use. The deciding factors should be coverage in your specific neighborhood and whether you want bundled services.

Buying a SIM Card at the Airport vs City

You can purchase a Thai SIM card immediately upon arrival at the airport or wait and buy one in the city. Each option has advantages.

At Suvarnabhumi Airport (BKK), all three carriers have kiosks on the arrivals level (Level 2) in the main concourse. The kiosks are open 24 hours and staffed by English-speaking representatives who can help you choose the right plan and activate the SIM. Tourist SIM cards at the airport cost 300 to 600 THB for 7 to 15 days of unlimited or high-speed data plus some call credit. The convenience is unbeatable: you walk out of the airport with a working Thai number. The downside is slightly higher prices compared to city shops and a limited selection of plans.

At Don Mueang Airport (DMK), carrier kiosks are also available in the arrivals area, though with fewer options than Suvarnabhumi.

In the city, you can buy SIM cards at official carrier shops (found in every mall), 7-Eleven stores, Big C, Lotus's, and independent phone shops. Carrier shops in malls offer the widest selection of plans and can help with SIM swaps, number changes, and plan changes. 7-Eleven sells basic SIM starter kits for 49 to 99 THB, which you then top up and register. This is the cheapest option but requires more setup.

All SIM cards in Thailand must be registered with a passport due to government regulations. At airport kiosks and carrier shops, the staff handles registration using your passport. If you buy at 7-Eleven, you must register the SIM through the carrier's app or website by uploading a photo of your passport and taking a selfie for verification. This process takes 15 to 30 minutes.

Recommendation: Buy a tourist SIM at the airport for immediate connectivity on your first day. Once settled, visit a carrier shop to switch to a longer-term plan that better suits your needs. The initial tourist SIM expense (300 to 600 THB) is minimal compared to the convenience of having navigation, translation apps, and Grab available from the moment you land.

Tourist SIM vs Long-Term Plans

Thailand offers two categories of mobile plans: tourist SIMs designed for short-term visitors and regular prepaid plans suitable for longer stays. Understanding the differences helps you choose the right option.

Tourist SIMs are designed for stays of 7 to 30 days and offer generous data allowances at a fixed price. A typical tourist SIM costs 300 to 600 THB and includes 7 to 15 days of unlimited data (with a high-speed quota of 5 to 15 GB before speed reduction), some voice minutes, and free incoming calls. The AIS Traveller SIM (599 THB) offers 10 days of unlimited data with 15 GB at high speed. TrueMove Tourist SIMs (299 to 599 THB) offer 8 to 15 days with similar data allowances. Tourist SIMs are available at airports and some convenience stores.

For stays longer than 2 weeks, a regular prepaid plan is more cost-effective. Thai prepaid plans operate on a pay-as-you-go basis: you buy credit (top up) and subscribe to monthly packages that deduct from your balance. Monthly packages offer far more value than pay-per-use rates.

Budget prepaid plans (200 to 300 THB per month) typically include unlimited calls within the same network, some cross-network minutes, and 3 to 10 GB of high-speed data with unlimited reduced-speed data afterward. Mid-range plans (300 to 500 THB per month) include 15 to 50 GB of high-speed data, unlimited calls to all networks, and some international calling credit. Premium plans (500 to 800 THB per month) include 50 to 100 GB of high-speed data or truly unlimited data, unlimited calls, and sometimes international roaming data.

To subscribe to a monthly plan, top up your balance at 7-Eleven (minimum 50 THB), through the carrier's app, or via online banking, then dial a code (e.g., *500* for AIS) or use the carrier's app to activate your chosen package. Plans auto-renew monthly if you have sufficient balance.

Topping up is easy and available everywhere. 7-Eleven and FamilyMart sell top-up cards starting at 50 THB. The carrier's app accepts credit card and online banking top-ups. Some banks' mobile apps also offer mobile top-up as a built-in feature. Your balance does not expire as long as you make at least one chargeable activity (call, text, or data use outside a package) within 90 days.

eSIM Options for Thailand

eSIM technology allows you to activate a mobile plan without a physical SIM card, which is especially useful for dual-SIM phones. All three Thai carriers now offer eSIM, and several international providers offer Thailand eSIMs that you can purchase before arrival.

AIS eSIM: Available at AIS shops (found in every major mall). Bring your passport and a compatible phone. The staff activates the eSIM in about 10 minutes. You can choose any regular prepaid plan. AIS eSIM works identically to a physical AIS SIM. AIS also offers a traveller eSIM that can be purchased online before arrival through the AIS website.

TrueMove H eSIM: Available at True shops. Same process as AIS: bring passport, choose plan, scan QR code, activate. TrueMove's eSIM is popular because of their strong 5G network in Bangkok. You can also purchase TrueMove eSIMs online through their website before traveling.

DTAC eSIM: Available at DTAC shops and can also be purchased online. DTAC's eSIM offering is straightforward with competitive pricing.

International eSIM providers like Airalo, Holafly, and Nomad offer Thailand data eSIMs that you can download before departure. Prices range from 5 to 50 USD depending on data allowance and duration. Airalo offers 5 GB for 7 days at about 10 USD, which is competitive with local tourist SIMs. The advantage is convenience: your phone connects to a Thai network immediately upon landing without visiting a kiosk. The disadvantage is that these eSIMs typically provide data only, no Thai phone number for calls and texts.

For dual-SIM users, the ideal setup is keeping your home country SIM in one slot (for receiving calls and texts on your regular number) and using a Thai SIM or eSIM in the other slot for local data and calls. This avoids roaming charges while staying reachable on your home number.

To check if your phone supports eSIM, look in Settings under Mobile/Cellular for an Add eSIM option. Most iPhone models from XS and newer support eSIM, as do many recent Android flagship phones. Budget and mid-range phones are less likely to support eSIM.

Home Internet Setup (Fiber, 5G Home)

For expats settling into Thailand, home internet is essential for remote work, streaming, and daily life. Thailand has excellent broadband infrastructure in urban areas.

Fiber optic internet is the standard for home connectivity in Bangkok, Chiang Mai, Phuket, and other cities. Three main providers compete for residential customers: AIS Fibre, True Online, and 3BB (Jasmine). Monthly prices range from 500 to 1,500 THB for speeds of 100 Mbps to 1 Gbps. Installation is typically free and takes 3 to 7 days to schedule.

AIS Fibre offers plans starting at 590 THB per month for 300 Mbps and up to 1,290 THB for 1 Gbps. Their network is reliable and customer service is good. True Online provides similar speeds and pricing, with the added benefit of bundles that include mobile service and TV. Their plans start at 499 THB for 200 Mbps. 3BB is often the cheapest option with plans from 390 THB per month.

To sign up, visit a provider shop in any mall with your passport and proof of address (lease agreement or residence certificate from immigration). The shop checks availability at your address and schedules installation. Most modern condominiums are pre-wired for fiber from at least one provider, often all three. Check with your building management about which providers are available, as this can influence which apartment you choose.

5G home internet is emerging as an alternative to fiber. AIS and True offer 5G home routers that provide internet through the mobile network. Speeds range from 50 to 300 Mbps depending on 5G coverage in your area. Monthly plans cost 500 to 1,000 THB. The advantage is no installation required and portability. The disadvantage is variable speeds and higher latency compared to fiber. This is a good option for temporary accommodations or areas without fiber coverage.

For digital nomads and remote workers, having both fiber internet at home and a generous mobile data plan provides redundancy. If your home internet goes down, you can tether from your phone. A 4G/5G router with a data-only SIM (about 500 THB per month for unlimited data) serves as an excellent backup connection.

Internet Speeds by City

Internet speeds in Thailand vary significantly by location, with major cities offering world-class connectivity and rural areas lagging behind.

Bangkok has the fastest and most reliable internet in Thailand. Average download speeds on fiber connections range from 150 to 500 Mbps, with top-tier plans reaching 1 Gbps. Mobile 5G speeds in central Bangkok regularly exceed 200 Mbps. The BTS and MRT stations have free WiFi. Bangkok's coworking spaces consistently deliver 50 to 200 Mbps upload and download. The city's extensive fiber infrastructure means almost every building has access to high-speed internet.

Chiang Mai has excellent internet in the city center and Nimmanhaemin area, popular with digital nomads. Fiber speeds match Bangkok at 100 to 500 Mbps. Mobile 4G is reliable throughout the city with growing 5G coverage. Coworking spaces like Punspace and CAMP offer fast connections. Rural areas outside Chiang Mai city have slower and less reliable connections.

Phuket has good internet in populated areas like Patong, Kata, and Phuket Town. Fiber is available in most developed areas with speeds of 100 to 300 Mbps. Some beach areas and hillside accommodations have limited options. 5G coverage is expanding in the main tourist zones. Remote beaches may only have mobile data available.

Koh Samui and Koh Phangan have surprisingly good internet in main towns and developed areas. Fiber is available in Nathon, Chaweng, and Lamai on Koh Samui, and in Thong Sala and Haad Rin on Koh Phangan. Speeds of 50 to 200 Mbps are common. More remote beaches and jungle areas rely on mobile data with variable speeds.

Pattaya offers fiber internet comparable to Bangkok in the city center and expat areas like Jomtien. Speeds of 100 to 500 Mbps are standard. Smaller cities like Khon Kaen, Udon Thani, and Chiang Rai have expanding fiber networks with speeds of 50 to 200 Mbps in city centers. Rural Thailand generally has 4G mobile data as the primary option, with speeds of 10 to 50 Mbps.

Speed testing resources include Speedtest.net (the standard) and Fast.com (Netflix's speed test). Most Thai ISPs deliver 80 to 90 percent of their advertised speeds, which is good by international standards. Peak-hour slowdowns (7 PM to 11 PM) can reduce speeds by 20 to 30 percent.