Thailand's Smallest Industries by Company Count in 2026
In short
Just 74 companies in Thailand fall under public administration, households as employers, and extraterritorial organizations combined, sections O, T and U. Thailand has 1,989,709 registered companies as of 7 July 2026. Those three sections equal just 0.0037 percent of that total. Water supply and waste management, section E, adds only 4,818 more, still under a quarter of one percent. Electricity, gas, steam and air conditioning supply, section D, is the fifth smallest at 7,833. Together the five smallest sections hold 12,725 companies, under two percent of the size of wholesale and retail trade alone.
Which industries have almost no registered companies in Thailand?
Three of Thailand's 21 industry sections barely register as businesses at all. Public administration and defense, section O, counts just 38 registered companies nationwide. Households as employers, section T, counts 32. Extraterritorial organizations and bodies, section U, counts only 4. Combined, these three sections hold 74 companies. Thailand's national total is 1,989,709 registered companies. The three sections together equal 0.0037 percent of that total. Water supply and waste management, section E, is the fourth smallest at 4,818 companies. That is still under a quarter of one percent of the total. Electricity, gas, steam and air conditioning supply, section D, rounds out the bottom five at 7,833 companies. None of this means these activities do not happen in Thailand. It means almost nobody incorporates a company to do them.
Registered companies in Thailand's five smallest industry sections
- Section U: Extraterritorial organizations and bodies4
- Section T: Households as employers32
- Section O: Public administration and defense38
- Section E: Water supply and waste management4,818
- Section D: Electricity, gas, steam and air conditioning supply7,833
Figures in registered companies.
The gap between the top three and the rest is real, not a charting error. Extraterritorial bodies, households and public administration together add up to fewer companies than one mid-sized manufacturer employs workers.
The five smallest industry sections against the national total
| Industry section | Registered companies | Share of national total |
|---|---|---|
| Section U: Extraterritorial organizations and bodies | 4 | 0.0002% |
| Section T: Households as employers | 32 | 0.0016% |
| Section O: Public administration and defense | 38 | 0.0019% |
| Section E: Water supply and waste management | 4,818 | 0.242% |
| Section D: Electricity, gas, steam and air conditioning supply | 7,833 | 0.394% |
| All registered companies in Thailand | 1,989,709 | 100% |
Registered companies by section, as of 7 Jul 2026.
Why the smallest sections are structurally small, not shrinking
These are not emerging industries waiting to be discovered. Public administration is delivered by government agencies, not private companies, so a healthy state needs fewer registered firms in section O, not more. Domestic household employment mostly runs on informal, undocumented pay, so section T will likely never grow much beyond a few dozen firms. Extraterritorial organizations are embassies, UN agencies and similar bodies, and Thailand hosts a fixed, small number of them by definition. Water and waste management is different. Section E holds 4,818 companies. Those firms reported over 146 billion baht in combined revenue, since municipal utilities and waste concessions in Thailand still lean on state and quasi-state operators rather than private registrants. Electricity, gas, steam and air conditioning supply tells a sharper version of the same story. Section D holds 7,833 companies. Those firms reported over 815 billion baht in combined revenue. Mining and quarrying, section B, sits just outside the five smallest at 8,231 companies. It still posted 448.9 billion baht in revenue, further proof that a thin registry does not mean thin output. An investor scanning this registry for white space should treat sections O, T and U as permanently thin and read sections E and D as proof that a low company count can still sit next to serious revenue.
Definitions
- Industry section
- One of 21 broad economic categories in the ISIC classification system that Thailand's registry uses to tag each company, identified by a single letter from A to U.
- Registered company
- A juristic person incorporated with the Department of Business Development, counted once under the industry section assigned to it.
- Aggregate share
- A section's entity count divided by the national total of all registered companies, expressed as a percent.
- Net margin
- Net profit as a share of revenue for companies that filed a financial statement. Not used as a headline figure here because sections with only a handful of companies produce a ratio that a single firm can dominate.
Assumptions
- Entity counts include every company classified to a section as of 7 July 2026, whether currently active or dormant.
- Sections O, T and U have so few companies that a single incorporation or closure moves their share meaningfully, so the counts should be read as a snapshot, not a trend.
- Revenue and net margin figures for sections with fewer than a few dozen companies are cited only as descriptive color, never as a ranked or headline statistic.
Methodology
Entity counts, revenue and net profit are aggregated from the DBD registry by industry section as of 7 July 2026, drawn from the market_section_insight table. A company is counted once, under the single ISIC section assigned to it by the registry. Every share and ratio in this page is recomputed here directly from the raw entity counts, not read from a pre-built percentage. Net margin figures for sections with fewer than a few dozen companies are excluded from the headline claims because a handful of firms can swing the ratio sharply.
How we verified this
- Summed entity_count for sections U, 4, T, 32, and O, 38, to get 74, then divided 74 by the national total of 1,989,709 to get 0.0037 percent.
- Divided section E's entity_count of 4,818 by 1,989,709 to get 0.242 percent, confirming it stays under 5,000 and under a quarter of one percent.
- Divided section D's entity_count of 7,833 by 1,989,709 to get 0.394 percent, confirming it is the fifth smallest of the 21 sections, with section B at 8,231 ranking sixth instead.
- Summed all 21 section entity_counts and got 1,986,489, matching the classified-company anchor in the data guide, which confirms the section table is internally consistent.
- Summed the five smallest sections, 4 plus 32 plus 38 plus 4,818 plus 7,833, to get 12,725, then divided by section G's 715,976 to get 1.78 percent, confirming the five smallest sections combined are under two percent of the size of wholesale and retail trade alone.
- Divided section G's 715,976 by the 12,725 combined total of the five smallest sections to get 56.27, confirming the largest section is more than 56 times the size of the five smallest sections put together.
References
- Department of Business Development. (2026). Registered juristic persons by industry section. Ministry of Commerce, Thailand. https://www.dbd.go.th/
- United Nations Statistics Division. (2008). International Standard Industrial Classification of All Economic Activities, Revision 4. https://unstats.un.org/unsd/classifications/Econ/Download/In%20Text/ISIC_Rev_4_publication_English.pdf
Frequently asked questions
Which industries have the fewest registered companies in Thailand?
Extraterritorial organizations, section U, has just 4. Households as employers, section T, has 32. Public administration and defense, section O, has 38. Together the three total 74 companies. Thailand counts 1,989,709 registered companies nationwide.
Why does public administration have so few registered companies?
Public administration is delivered directly by government agencies, so it is rarely structured as a registered private company in the DBD registry, which only counts juristic persons, not government bodies.
Is water and waste management a small industry in Thailand?
By company count, yes. Section E holds 4,818 registered companies. That is 0.242 percent of the national total. Its total revenue exceeds 146 billion baht, real economic activity concentrated in a small number of firms.
What is the largest industry section for comparison?
Wholesale and retail trade, section G, has 715,976 registered companies. That is more than 56 times the combined count of the five smallest sections put together.
Cite this page
Chatpong L. (2026). Thailand's Smallest Industries by Company Count in 2026. Max Data Insights. https://maxdatathailand.com/insights/thailands-smallest-business-sectors-2026
Data & corrections
Download the data (CSV)Spot something off, or want to ask about the data? Email insights@maxsolutions.co.th. We publish corrections.
Written by
Chatpong L.Founder, Max Data, Max Solutions Co., Ltd.
Chatpong L. leads Max Data, a company-intelligence platform built on Thailand's official business registry. He writes about the structure of the Thai economy using primary registry data. His work covers company formation, industry concentration, and regional business activity.
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This page reports company-level and aggregate statistics only. It names no individuals and makes no claims about any person. Figures are provided for information and may be revised as source data updates.