Service guide
How a factory license in Thailand works: the Ror Ngor 4 under the Factory Act, official fees by machine power, the 30 day review, and the e-License route.
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The official fee for a factory license in Thailand scales with machine power. The government service record for the Section 12 licence publishes the full schedule, from 1,000 baht for an operation with no machinery to 145,000 baht at the top of the range. Professional fees for a firm that manages the application sit on top and depend on the factory category, the site, and how much of the environmental documentation already exists.
Official factory licence fees by machine power
Selected tiers from the published fee schedule for the factory operation licence (Ror Ngor 4). The full schedule continues in steps up to 145,000 baht.
| Item | Official fee |
|---|---|
| No machinery | 1,000 baht |
| Under 50 horsepower | 1,500 baht |
| 50 to under 100 horsepower | 3,000 baht |
| 100 to under 200 horsepower | 5,000 baht |
| 200 to under 300 horsepower | 7,000 baht |
| Top of the published schedule | 145,000 baht |
Source: Government service record, Section 12 factory licence
Checked August 2026
The Factory Act sorts factories into categories, and the licence requirement under Section 12 attaches to the categories the Act reserves for prior approval. Whether a planned operation needs the full licence, a notification, or nothing at all is the first question a firm settles, because it decides the whole timeline.
A Bangkok factory files at the Department of Industrial Works service centre; a factory anywhere else files at the provincial industry office for the province where the site stands. The application form is the Ror Ngor 3, filed in two originals in Bangkok and three in the provinces. There is also an online route: the e-License system at the i-Industry portal, which requires registering on the portal first and lists a one month handling time.
Confirm the category
The factory list attached to the Act decides whether the operation needs a Section 12 licence at all. Getting this wrong in either direction is expensive.
Prepare the site and process documentation
The document list includes a production process chart identifying where wastewater, air emissions, industrial waste and other pollution arise, with the type, quantity and treatment method for each. This is the substantive review work.
File the Ror Ngor 3
Two originals in Bangkok at the Department of Industrial Works, three at a provincial industry office, or through the e-License system after registering on the i-Industry portal.
Officials review29 to 30 days
The published review time is 29 days for a complete paper application and 30 days through e-License. Unclear documents restart the clock through requests for clarification.
Pay the fee and start up
The licence fee follows the machine-power schedule. Test runs of machinery before full operation carry their own notification duty under the Act.
Your options
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International boutique law firm in Bangkok and Phuket, providing legal and tax services to investors, businesses, and private clients across Thailand
฿4,000–12,000 / hour
Thai-English speaking law firm in Hua Hin providing family law, business law, real estate, wills, and immigration services.
Note: BOI promotion changes the sequence, not the licence
A promoted project still needs its factory licence; the promotion certificate and the licence run as parallel workstreams with different agencies. Firms coordinating both usually sequence the BOI application first, because the promotion terms can change the machinery list the licence application describes. The background on what promotion actually grants is in our guide to BOI promotion in Thailand.
The legal work concentrates in three places. First, the category decision under the factory list, which decides the route. Second, the environmental file: the production chart with its pollution points and treatment methods is reviewed on substance, and weak treatment answers are the common reason applications stall. Where a project needs a formal environmental assessment, that runs through environmental law specialists before the licence file is complete. Third, the building and zoning fit: a factory needs a site where industrial use is lawful, and the licence review checks the location.
A small operation renewing in place may need nobody. The cases that justify fees: a first licence for a new site, a foreign-owned operation structuring through a Thai company, category questions at the licence threshold, an environmental file that needs building from scratch, or a licence on a construction deadline. Factory licensing sits with corporate and business law firms in Thailand, and where the operating company is still being formed, the licence work runs alongside company registration in Thailand.
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International boutique law firm in Bangkok and Phuket, providing legal and tax services to investors, businesses, and private clients across Thailand
฿4,000–12,000 / hour
Thai-English speaking law firm in Hua Hin providing family law, business law, real estate, wills, and immigration services.
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International boutique law firm in Bangkok and Phuket, providing legal and tax services to investors, businesses, and private clients across Thailand
฿4,000–12,000 / hour
Thai-English speaking law firm in Hua Hin providing family law, business law, real estate, wills, and immigration services.
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