Thai Industry Codes With the Highest Large-Company Share, 2026
In short
Among Thailand's sizeable industry codes, 29309, the catch-all class for other motor vehicle parts and accessories, has the highest large-company share at 12.34 percent, nearly 18 times the national rate of 0.70 percent. Basic inorganic chemicals ranks second at 12.13 percent, and basic aluminium manufacturing ranks third at 10.60 percent. Seven of the nine steepest codes sit inside manufacturing. Sizeable means at least 500 registered companies, a bar only 413 of Thailand's 1,228 five digit codes clear. Drop that bar to 100 companies and a 169 firm sugar refining code claims 29.59 percent, a swing built on just 50 companies.
Which industry code has the highest share of large companies?
Rank Thailand's roughly 1,228 five digit TSIC codes by raw large-company count and wholesale and retail trade wins almost by default, because it simply has more companies of every size on the books (DBD, 2026). Rank the same codes by large-company share, the percentage of registered firms in that code classified large, and a sharper picture appears. Restrict the comparison to codes with at least 500 registered companies, a floor cleared by 413 of the 1,228, and TSIC 29309 leads at 12.34 percent. That code covers manufacturers of motor vehicle parts and accessories that do not fit a more specific class, a fitting home for Thailand's dense auto parts supply base. Basic inorganic chemicals, TSIC 20113, follows at 12.13 percent. Basic aluminium and aluminium products manufacturing, TSIC 24202, holds third at 10.60 percent. Prepared feed for livestock, TSIC 10802, sits fourth at 8.38 percent. Electronic components manufacturing, TSIC 26109, rounds out the top five at 7.99 percent. Every code in the top nine runs at least seven times the national large-company rate of 0.70 percent.
Large-company share by TSIC code, sizeable codes only
- 29309 Motor vehicle parts, other12
- 20113 Basic inorganic chemicals, other12
- 24202 Basic aluminium products11
- 10802 Prepared feed for livestock8
- 26109 Electronic components, other8
- 20131 Plastics in primary forms7
- 24109 Basic iron and steel, other6
- 86101 Hospital activities6
Figures in percent of registered companies classified large.
All eight codes clear five percent large, against a national rate of 0.70 percent across every size classified company.
Top nine sizeable TSIC codes by large-company share
| TSIC code | Industry | Section | Registered firms | Large firms | Large share |
|---|---|---|---|---|---|
| 29309 | Motor vehicle parts and accessories, other | Manufacturing | 3,461 | 427 | 12.34% |
| 20113 | Basic inorganic chemicals, other | Manufacturing | 503 | 61 | 12.13% |
| 24202 | Basic aluminium and aluminium products | Manufacturing | 519 | 55 | 10.60% |
| 10802 | Prepared feed for livestock | Manufacturing | 728 | 61 | 8.38% |
| 26109 | Electronic components, other | Manufacturing | 1,765 | 141 | 7.99% |
| 20131 | Plastics in primary forms | Manufacturing | 1,110 | 73 | 6.58% |
| 24109 | Basic iron and steel, other | Manufacturing | 1,969 | 114 | 5.79% |
| 86101 | Hospital activities, general | Human health and social work | 2,424 | 137 | 5.65% |
| 45101 | Sale of new passenger cars, pickups and vans | Wholesale and retail trade | 10,006 | 520 | 5.20% |
TSIC codes with at least 500 registered companies, ranked by large-company share, as of 17 Jul 2026.
Why a size floor changes the ranking
Drop the 500-company floor and the ranking changes, and it keeps changing the smaller the codes get. Restricted to codes with at least 100 registered companies, TSIC 10722, sugar refining, leads at 29.59 percent large. That code carries only 169 registered companies. Just 50 of them are large. A handful of big refiners can swing a percentage that small. Drop the company count further and the swings turn extreme. Thailand has 257 industry codes with fewer than 20 registered companies each, and one of them posts a large-company share above 89 percent on a total of just 19 firms. Vegetable and animal oil manufacturing, TSIC 10420, shows 22.52 percent large on a thin base of 373 firms. Codes that small make for a dramatic headline and a shaky ranking. The 500-company floor used in the main ranking trades a few eye catching outliers for a result that reflects an actual industry structure, not the arithmetic of a small sample. Even with that floor in place, manufacturing still dominates. Seven of the top nine codes, and all six of the top six, sit inside section C.
Why this matters
A large-company share this high inside auto parts, chemicals, aluminium, electronics and hospital care points to industries built around scale from the start, not ones a small operator can enter easily and grow into. Suppliers to Thailand's vehicle assembly plants typically need certified quality systems, large fixed capital and a handful of anchor customers before they book their first order, and that raises the floor for who can compete. A hospital needs specialized equipment, licensed staff and heavy upfront capital before it can treat its first patient, for much the same reason. A new car dealership works differently. It appears in the top nine mostly because it serves an enormous, well capitalized customer base at massive volume, not because the business itself demands scale to start. The practical lesson for a supplier, a lender or a policymaker is the same either way. Company count alone tells you how crowded an industry is. Large-company share tells you how hard it is to compete there once you are already inside it.
Definitions
- Size band
- The DBD registry's classification of a company into micro, small, medium or large, based on its most recently filed financial statement.
- Large-company share
- The count of large size band companies in a TSIC code divided by all size classified companies in that same code, expressed as a percentage.
- Sizeable industry code
- In this analysis, a 5-digit TSIC code with at least 500 registered, size classified companies. Only 413 of Thailand's 1,228 codes meet this bar.
- TSIC code
- A 5-digit code in the Thailand Standard Industrial Classification, based on ISIC, that identifies a specific industry activity. All 5-digit TSIC codes roll up into one of 21 lettered sections.
- Size classified company
- A company that has been assigned a size band. Companies with no filed financial statement are not size classified and are excluded from every share in this analysis.
Assumptions
- For each TSIC code, entity_count reflects only companies with an assigned size band, so large-company share is measured against size classified companies, not every company ever registered under that code.
- The 500-company floor is a methodological choice made for this analysis to reduce small-sample swings. TSIC 29309 stays first for floors between 500 and 1,000 registered companies, but loosening the floor below 500 surfaces smaller codes with even higher percentages instead.
- Without any company-count floor, the single highest large-company share in the registry is 89.47 percent, held by a code with only 19 registered companies. That figure illustrates small-sample volatility. It is not treated as a ranking result because a code that thin cannot support a reliable share estimate.
- Dormant, size classified companies remain in both the numerator and denominator, so a code with many inactive large filers can still show a high share.
Methodology
Large-company share is the count of DBD size band large companies in a 5-digit TSIC industry code divided by all size classified companies in that code, drawn from the DBD registry as of 17 July 2026. The ranking is restricted to codes with at least 500 registered companies, a threshold chosen because the registry-wide median code holds only 194 companies and shares computed on a few dozen firms swing sharply on one or two large filers. Entity counts reflect only companies with an assigned size band. Industry names for 5-digit TSIC codes are not stored in the source table and were confirmed against Thailand's TSIC 2009 classification and public company registry listings.
How we verified this
- National large-company rate recomputed as 13,875 divided by 1,986,709 equals 0.6982 percent, stated as 0.70 percent.
- TSIC 29309 share recomputed as 427 divided by 3,461 equals 12.338 percent, stated as 12.34 percent, confirmed as the maximum among the 413 codes with entity_count of 500 or more.
- The multiple was recomputed as 12.34 divided by 0.6982 equals 17.67, stated in the text as nearly 18 times.
- TSIC 20113 share recomputed as 61 divided by 503 equals 12.126 percent, stated as 12.13 percent, confirmed as second highest.
- TSIC 24202 share recomputed as 55 divided by 519 equals 10.597 percent, stated as 10.60 percent, confirmed as third highest among the 413 sizeable codes.
- TSIC 10802 share recomputed as 61 divided by 728 equals 8.379 percent, stated as 8.38 percent, confirmed as fourth highest among the 413 sizeable codes.
- The full ranking of all 413 sizeable codes by large-company share was re-queried directly against market_tsic_insight, which surfaced TSIC 24202 and TSIC 10802 as the true third and fourth place codes, correcting an earlier draft that had skipped both.
- The 413-of-1,228 sizeable code count was recomputed by counting TSIC rows with entity_count at or above 500 against the full 1,228-row table, and the registry median entity_count of 194 was confirmed separately.
- TSIC 10722 was recomputed as 50 divided by 169 equals 29.585 percent, stated as 29.59 percent, and confirmed as the highest share among the 1,228 codes with at least 100 registered companies. With no floor at all, one code with only 19 registered companies recomputes to 17 divided by 19 equals 89.47 percent, the true registry maximum, cited in the text as an illustration of small-sample volatility rather than as a ranking result.
References
- Department of Business Development. (2026). Registered juristic persons and company size classification. Ministry of Commerce, Thailand. https://www.dbd.go.th/
- OECD. (2026). Financing SMEs and Entrepreneurs 2026: Thailand. OECD Publishing. https://www.oecd.org/en/publications/financing-smes-and-entrepreneurs-2026_075d8058-en/full-report/thailand_a1b1b4e6.html
Frequently asked questions
Which Thai industry code has the highest share of large companies among sizeable industries?
TSIC 29309, the catch-all class for other motor vehicle parts and accessories, at 12.34 percent large among its 3,461 registered companies.
What counts as a sizeable industry code in this ranking?
A TSIC code with at least 500 registered companies. Only 413 of Thailand's 1,228 five digit codes clear that bar, against a registry-wide median of 194 companies per code.
Why does the ranking change without a size floor?
Small codes swing hard on a few filers. Among codes with at least 100 registered companies, sugar refining, TSIC 10722, has only 169 firms, and 50 large ones push its share to 29.59 percent. Codes with fewer than 20 registered companies swing even harder. One such code reaches above 89 percent large on a total of just 19 firms.
What does a company's size band mean in the DBD registry?
DBD assigns every company with a filed financial statement to a micro, small, medium or large band based on figures in its most recent filing. Large-company share here is the large band divided by every size classified company in that TSIC code.
Cite this page
Chatpong L. (2026). Thai Industry Codes With the Highest Large-Company Share, 2026. Max Data Insights. https://maxdatathailand.com/insights/thai-industry-codes-with-the-highest-share-of-large-companies-2026
Data & corrections
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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.