Establishing a factory in Thailand requires compliance with the Factory Act B.E. 2535 (1992) and its amendments. The law classifies factories into three categories based on the level of government control:
Type 1: No license required; operators must comply with relevant regulations
Type 2: No license required, but prior notification to authorities is mandatory
Type 3: A factory operation license (Ror.Ngor.4) is required
The classification depends on several key factors, including the type of business, machinery horsepower, number of workers, production volume, environmental and safety risks, and factory location. Larger-scale or higher-risk operations are typically classified as Type 3 and are subject to stricter regulatory control.
For Type 3 factories, operators must apply for a license by preparing essential documents such as the application form (Ror.Ngor.3), machinery details, production process information, land ownership or lease documents, and an Environmental Impact Assessment (EIA) report if required. Authorities will then review the documents and conduct a site inspection before granting approval. The process generally takes around 60–90 days.
In addition, certain industries—such as food processing, chemicals, and recycling—may be subject to additional regulations. If the factory is located within an industrial estate, approval from the Industrial Estate Authority of Thailand (IEAT) may also be required.
Understanding these legal requirements from the outset helps entrepreneurs plan effectively, reduce risks, and ensure smooth and compliant business operations in the long term.
