Thai Industry Sections With the Most Medium Companies 2026
In short
Water supply and waste management carries the highest share of medium-sized companies of any Thai industry section, at 3.78 percent as of 17 July 2026. Manufacturing follows at 3.52 percent and electricity and gas at 3.37 percent. Other services sits at the bottom of the measurable sections at just 0.46 percent, so water and waste runs more than eight times as medium heavy. Across the whole economy only 1.96 percent of companies with a size band are classified as medium.
Which sector has the highest share of medium companies?
Water supply and waste management tops every other Thai industry section on one specific measure: the share of its companies classified as medium, at 3.78 percent (DBD, 2026). Manufacturing is close behind at 3.52 percent, then electricity and gas at 3.37 percent. Agriculture, forestry and fishing and wholesale and retail trade both clear 2.6 percent. A medium company sits just below the large threshold, so a high medium share flags a sector where a meaningful slice of operators have already scaled past small but have not yet crossed into large. Water utilities, factories and power operators all run capital-heavy, regulated businesses, and that combination tends to push a bigger share of their companies into the middle band rather than leaving them stuck at micro scale. Sections built on light, easily replicated services barely produce any medium companies at all.
Share of companies classified as medium, by industry section
- Water and waste4
- Manufacturing4
- Electricity and gas3
- Agriculture, forestry and fishing3
- Wholesale and retail trade3
- Financial and insurance2
- Mining and quarrying2
- Transportation and storage2
- Human health and social work2
- Accommodation and food service1
- Information and communication1
- Administrative and support1
- Construction1
- Arts and entertainment1
- Real estate1
- Professional, scientific and technical1
- Education1
- Other services0
Figures in percent of section companies that are medium.
Public administration, households as employers and extraterritorial organizations are left off this chart. Together they hold only 74 registered companies nationwide, too few to score a meaningful share.
Medium companies by industry section, ranked by share
| Industry section | Companies | Medium companies | Share medium |
|---|---|---|---|
| Water and waste | 4,818 | 182 | 3.78% |
| Manufacturing | 230,396 | 8,109 | 3.52% |
| Electricity and gas | 7,833 | 264 | 3.37% |
| Agriculture, forestry and fishing | 19,259 | 534 | 2.77% |
| Wholesale and retail trade | 716,066 | 18,789 | 2.62% |
| Financial and insurance | 35,577 | 759 | 2.13% |
| Mining and quarrying | 8,231 | 170 | 2.07% |
| Transportation and storage | 85,303 | 1,754 | 2.06% |
| Human health and social work | 17,294 | 318 | 1.84% |
| Accommodation and food service | 83,608 | 989 | 1.18% |
| Information and communication | 52,537 | 592 | 1.13% |
| Administrative and support | 100,711 | 1,116 | 1.11% |
| Construction | 283,564 | 2,712 | 0.96% |
| Arts and entertainment | 18,486 | 167 | 0.90% |
| Real estate | 149,618 | 1,207 | 0.81% |
| Professional, scientific and technical | 138,982 | 1,106 | 0.80% |
| Education | 13,897 | 78 | 0.56% |
| Other services | 20,455 | 95 | 0.46% |
Total companies with a size band, medium companies and their share, per section, as of 17 Jul 2026.
Why the medium-company share matters
A medium company has already survived the hardest climb in business, the move off a micro footing, but has not yet reached the scale where it dominates a market. Where that group concentrates says something real about how a sector grows. Water supply and waste management is small in total headcount, just 4,818 registered companies, yet 182 of them are medium, a rate roughly four times the economy-wide average of 1.96 percent. Treatment plants, waste haulers and utility operators need fixed infrastructure before they can take on a single contract, so a company in this sector tends to arrive already mid-sized rather than grow into it slowly from a home office. Other services runs the opposite pattern. It holds 20,455 companies, yet only 95 are medium, a 0.46 percent share, because most of the businesses inside it, repair shops, personal services, small trade associations, can operate indefinitely at micro or small scale without ever needing the balance sheet of a medium firm. A lender or a supplier scanning sectors for graduating mid-market customers should weight the water and waste, manufacturing and electricity sectors far above their small company counts would suggest.
Definitions
- Medium company
- The third of four DBD size bands, above small and below large, assigned using capital, revenue and asset thresholds drawn from Thailand's MSME classification rules.
- Share of medium companies
- The count of medium companies in a section divided by all companies in that section with an assigned size band, expressed as a percentage.
- Industry section
- One of the 21 top level letters, A through U, in the International Standard Industrial Classification, each grouping many 5 digit industry codes.
- TSIC
- The Thailand Standard Industrial Classification, the 5 digit industry coding system that DBD assigns to every registered company and that rolls up into the 21 lettered sections.
Assumptions
- A company's size band and section come from its most recent filed status in the registry, so a company that never filed a financial statement may lack a size band and is excluded from that section's total.
- Public administration, households as employers and extraterritorial organizations are excluded from the ranked chart and table because each holds fewer than 40 companies, too few for a stable share, though their raw counts are documented in the methodology.
- The live query behind this page returned 38,942 medium companies nationwide, slightly above an earlier published cut of 38,926, reflecting routine registry updates between the two data pulls. All shares in this page use the newer, live figure.
- Size bands reflect a single point in time. A section's share of medium companies can shift as individual companies file new statements and cross a threshold.
Methodology
Medium-company share is the count of companies coded as medium divided by all companies with an assigned size band in a section, computed from Thailand's Department of Business Development registry as of 17 July 2026. Figures are aggregated from 5 digit TSIC industry codes up to their parent 1 letter section, since 5 digit industry names are not published in this dataset. Size bands, running micro, small, medium and large, follow the registry's own classification. Public administration, households as employers and extraterritorial organizations are reported in the underlying data but dropped from the ranked chart and table because each holds fewer than 40 registered companies, too few for a stable share.
How we verified this
- Water and waste: 182 medium companies of 4,818 total equals 182 divided by 4818 times 100, or 3.78 percent, the highest of the 21 sections.
- Manufacturing: 8,109 medium companies of 230,396 total equals 3.52 percent, the second highest share.
- Other services: 95 medium companies of 20,455 total equals 0.46 percent, the lowest of the 18 scored sections, and 3.78 divided by 0.46 equals 8.2, so water and waste runs more than eight times as medium heavy.
- Summed across all 21 sections, medium companies total 38,942 of 1,986,709 companies with a size band, a 1.96 percent economy-wide share, close to the registry's previously published national medium-company share of 2.0 percent from an earlier data cut.
- All 18 scored sections were re-sorted by share of medium companies in descending order and the sequence matches the published chart and table.
- The 21 section entity counts sum to 1,986,709, matching the registry's total company count with an assigned size band.
References
- Department of Business Development. (2026). Registered juristic persons and enterprise size classification. Ministry of Commerce, Thailand. https://www.dbd.go.th/
- Office of Small and Medium Enterprises Promotion. (2020). Ministerial regulation on MSME classification criteria. Ministry of Industry, Thailand. https://en.sme.go.th/en/
Frequently asked questions
Which Thai industry section has the highest share of medium companies?
Water supply and waste management, where 3.78 percent of registered companies are classified as medium, ahead of manufacturing at 3.52 percent and electricity and gas at 3.37 percent.
Which industry section has the lowest share of medium companies?
Other services, at 0.46 percent, among the 18 sections large enough to score a stable share. Education is close behind at 0.56 percent.
What share of Thai companies overall are medium sized?
1.96 percent, or 38,942 of the 1,986,709 companies with an assigned size band, as of 17 July 2026.
How is a company classified as medium in Thailand?
The DBD registry assigns each filed company to a micro, small, medium or large size band using capital, revenue and asset thresholds set under Thailand's MSME classification rules, sitting between the small and large bands.
Cite this page
Chatpong L. (2026). Thai Industry Sections With the Most Medium Companies 2026. Max Data Insights. https://maxdatathailand.com/insights/thai-industry-sections-with-the-highest-share-of-medium-companies-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.