Thailand's mobile market revolves around three brands: AIS, TrueMove H (True) and dtac. But True and dtac merged into one company in 2023, and in October 2025 the two brands' networks were combined into a single network. For a traveler, Thailand effectively has two networks: AIS and True-dtac. In Q2 2026, AIS reported 47.1 million mobile subscribers and True Corporation 48.6 million, and both run their main 5G layer on the 2600 MHz band (band n41). This guide uses the operators' own results and announcements plus Ookla speed data to explain how the Thai operators differ, and how to check which network your travel eSIM connects to.
If you want a Thai connection ready before you fly, see the Coral eSIM plans for Thailand and pick the data allowance that fits your stay. The supported networks are listed on the product page.
Thailand mobile operators: three brands, two main companies
These are Thailand's main mobile operators. Subscriber figures come from each company's Q2 2026 results, published in August 2026.
| Brand | Company | Mobile subscribers | of which 5G |
|---|---|---|---|
| AIS | Advanced Info Service | 47.1 million | 19.7 million |
| TrueMove H and dtac | True Corporation | 48.6 million (both brands) | 19.3 million |
True Corporation was formed when True and dtac completed their amalgamation on 1 March 2023. Both the TrueMove H and dtac brands survived the merger, and tourist SIMs are still sold under each name. The third company, state-owned NT (National Telecom), was created in 2021 by merging TOT and CAT. NT holds a 700 MHz licence and, since 2023, has let an AIS subsidiary use part of it while AIS builds the base stations. We could not find NT's subscriber count in official sources.
The rules for buying a local SIM and where to find the airport counters are covered in Thailand SIM cards for travelers.
True and dtac One Network: same signal under either operator name
In an announcement on 10 October 2025, True said it had integrated the True and dtac networks into "a single, unified" network. Spectrum from both brands is pooled, so TrueMove H and dtac customers now share the same base stations and frequencies.
What this means for you: even if your phone's network list shows both "TrueMove H" and "DTAC", the signal comes from essentially the same network. Switching between TrueMove H and DTAC when the connection is poor may not help. If you want to try a different network, switch between AIS and the True side, since that is a genuine comparison.
Also, the 850 MHz band that True operated with NT reached the end of its contract on 3 August 2025. True said this does not cause SIMs to be deactivated.
Thai operators run 5G mainly on 2600 MHz (n41)
In the 2020 spectrum auction, AIS won 700 MHz, 2600 MHz (100 MHz of bandwidth) and 26 GHz, and launched 5G on 2600 MHz in February 2020. AIS's official FAQ also says its 5G runs on the 700 MHz, 2600 MHz and 26 GHz bands. True also runs 5G on 2600 MHz, and in October 2025 it announced tests using 90 MHz of 2600 MHz spectrum combined with the 2300 MHz band.
In 3GPP terms, 2600 MHz is 5G band "n41" and 700 MHz is "n28". That is different from the 3.5 GHz band (n78) used for most 5G in Japan and South Korea. A phone that gets 5G at home may not get 5G in Thailand if it does not support n41; it will fall back to 4G.
What to check on your phone
- 5G bands: look for "n41" in the manufacturer's spec sheet. To use the wide-area 700 MHz 5G layer you also need "n28"
- Carrier lock: a locked phone cannot use a travel eSIM (how to check if your phone is unlocked)
- A 5G-enabled plan: even with n41 support, a 4G-only plan will not connect to 5G
Both operators added spectrum in 2025: True obtained new 2300 MHz and 1500 MHz licences and AIS a 2100 MHz licence, so the frequencies available for 4G and 5G keep growing.
Thailand mobile operators compared: coverage and speed
On coverage, AIS said in its full-year 2025 results (February 2026) that its 5G network covers more than 95% of Thailand's population. True has published a target of expanding its 5G population coverage to 98% by 2026, but we could not find an achieved figure in official sources.
For speed, Ookla's Speedtest Global Index gives a country-level view. In August 2026, Thailand's median mobile download speed was 134.45 Mbps, with 24.68 Mbps upload and 20 ms latency, ranking 26th in the world. The global median for the same month was 172.04 Mbps. That is plenty for maps, ride-hailing apps and social video.
By operator, AIS announced in March 2026 that it was named "Best Mobile Network" and "Best 5G Network" in Ookla's assessment for the second half of 2025. This comes from AIS's own announcement, and we could not confirm per-operator figures on Ookla's public pages. We also could not find operator-level quality measurements from the Thai regulator NBTC on its website. At the moment, there is little primary data that settles the speed gap between operators in hard numbers.
Free Wi-Fi and the TDAC arrival card that you need to submit before landing are covered in Wi-Fi in Thailand.
Which Thai operator does your travel eSIM use? How to check
Most travel eSIMs connect by borrowing a Thai operator's network. Which one depends on the product: some use a single operator, others support several. On the Coral eSIM Thailand product page, the supported networks shown are AIS (5G), TrueMove H (5G) and DTAC (5G) as of 26 September 2026. The listing may differ between plans, so check the section for the plan you buy.
- Before buying: check the supported networks on the product page for operator names and 5G support
- Check your phone: confirm n41 (and n28) in the spec sheet
- After landing: on iPhone, go to Settings, Cellular (Mobile Data), your travel line, then Network Selection to see the current operator. On Android the wording varies by model, but look for "Network operators" in the SIM settings
- If it is slow: turn off automatic selection and compare AIS with the True side (TrueMove H or DTAC). Switching between TrueMove H and DTAC makes little difference because they share one network
- Leave the APN alone: it is normally set automatically when you install the eSIM. Change it only if the instructions tell you to (eSIM APN settings)
For the steps after arrival, see the Thailand eSIM guide, and if speeds are poor, see what to do when your eSIM is slow. You can check the supported networks on the Coral eSIM plans for Thailand.
Thailand mobile operators: frequently asked questions
Which mobile operator in Thailand is the fastest?
We could not find official, public measurements comparing speed by operator. AIS has announced that it was named "Best Mobile Network" and "Best 5G Network" in Ookla's assessment for the second half of 2025. Nationally, the median mobile download speed in August 2026 was 134.45 Mbps.
Are TrueMove H and dtac separate networks?
Both brands are run by True Corporation, and their networks were integrated into one in October 2025. Customers of both brands share the same base stations and frequencies. If you want to try another network, switch between the True side and AIS.
Can I use Thai 5G with a phone from home?
Thai 5G runs mainly on 2600 MHz (band n41), and AIS also uses 700 MHz (n28). If your phone's spec sheet lists n41, it can use Thai 5G in terms of frequency. This differs from n78, which many countries use, so check before you travel.
Which operator should my travel eSIM connect to?
If a plan supports both AIS and the True side, you can switch between them when the connection is poor. First confirm the plan supports 5G, then check the operator names in the supported networks section. The Coral eSIM Thailand product page lists AIS, TrueMove H and DTAC 5G.
How do I check or change the operator I am connected to?
On iPhone, go to Settings, Cellular (Mobile Data), your travel line, then Network Selection. Turn off automatic selection to choose another operator from the list. On Android the wording varies by model; look for "Network operators" in the SIM settings.
In Thailand, choose your eSIM by AIS vs True and by n41 support
Thailand looks like it has three operators, but TrueMove H and dtac now share one network, so the real choice for a traveler is between AIS and the True side. Both run their main 5G layer on 2600 MHz (n41), and national speeds are more than enough for everyday use. So first make sure your phone supports n41, then check whether your plan connects to AIS, the True side, or both. After landing, check the connected operator once under Network Selection, and if it is slow, compare AIS with the True side.
See the plans and supported networks for Thailand on the Coral eSIM plans for Thailand, or browse other destinations in all plans.
