Factory Act B.E. 2535 — Department of Industrial Works
Factory License Services
in Thailand
Operating a factory in Thailand requires a valid license from the Department of Industrial Works. B-Accounting guides manufacturers, industrial operators and foreign investors through factory license applications, renewals, expansions and ongoing regulatory compliance.
3
Factory Categories
30+
Days Processing (Type 3)
13+
Years of Experience
1
Dedicated Advisor
DIW
Department of Industrial Works
What Is a Factory License in Thailand?
Legal Authorization for Industrial & Manufacturing Operations
The Factory Act B.E. 2535 (1992) governs all industrial and manufacturing operations in Thailand. Any business operating machinery with an aggregate power of 5 horsepower or more, or employing 7 or more workers in a production process, is classified as a factory and must obtain the appropriate authorization from the Department of Industrial Works (DIW).
Operating without the required factory license or in breach of license conditions is a criminal offense under Thai law, exposing operators to significant fines, forced closure and personal liability for directors. Compliance with environmental, safety and operational standards is mandatory throughout the license period.
B-Accounting provides full-service factory license support for foreign-owned manufacturers, joint ventures and Thai companies — from initial classification and application through to ongoing renewals and compliance management.
Mandatory for factories with 5+ HP machinery or 7+ production workers
Three factory categories with different requirements and procedures
Issued by the Department of Industrial Works (DIW)
Environmental, health and safety compliance required
Combinable with BOI promotion and Free Zone operations
Factory Classification
Three Categories Under the Factory Act
The Factory Act classifies industrial operations into three categories based on size, machinery power and operational complexity. Each category carries different licensing obligations.
01
Notify Only
Type 1 — Notification Required
The smallest category of factory operations. A notification to the DIW is sufficient — no formal license is required prior to commencing operations.
Threshold: 5–20 HP or 7–20 workers
- Small-scale food processing units
- Light assembly operations
- Small garment and textile workshops
- Minor woodworking and crafts facilities
02
Pre-Operation Notice
Type 2 — Pre-Operation Notice
Medium-scale factories must notify the DIW before commencing operations, but do not require formal prior approval. Operations may commence after a 30-day waiting period.
Threshold: 21–50 HP or 21–50 workers
- Medium-scale food and beverage production
- Plastics and rubber processing
- Metal fabrication and light engineering
- Printing and packaging operations
03
License Required
Type 3 — Full License Required
Large-scale or potentially hazardous factories require a full factory license from the DIW before any operations may commence. Application undergoes formal review including site inspection.
Threshold: 50+ HP or 50+ workers
- Heavy manufacturing and automotive
- Chemical and petrochemical plants
- Large-scale food processing facilities
- Electronics and component manufacturing
- Pharmaceutical production facilities
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Operating Without Authorization — Penalties Under the Factory Act
Operating a Type 2 or Type 3 factory without the required notification or license is a criminal offense. Penalties include fines of up to THB 200,000 and imprisonment of up to 2 years for individuals, and forced factory closure orders. Directors and responsible persons may face personal criminal liability.
Our Services
Full-Service Factory License Support
From initial factory classification through to license issuance, annual compliance and expansion approvals — B-Accounting manages the full scope.
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Factory Classification & Feasibility
We assess your operations, machinery specifications and workforce to determine the correct factory category and applicable licensing pathway.
- Type 1 / 2 / 3 classification determination
- HP and worker threshold analysis
- Environmental and safety pre-assessment
- Site and zoning compliance review
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New Factory License Application
We prepare and submit the full factory license application to the DIW, coordinating all required technical, environmental and safety documentation.
- Application form preparation
- Factory layout and equipment schedules
- Environmental impact documentation
- DIW submission and follow-up
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DIW Liaison & Inspection Support
We represent your company before the DIW throughout the review process, including preparation for and attendance at official site inspections.
- DIW officer liaison
- Site inspection coordination
- Query and objection responses
- Permit condition negotiation
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License Renewals & Amendments
Factory licenses must be periodically renewed and updated when operations change. We manage all renewals and amendments to keep your license current.
- Periodic renewal management
- Machinery addition and amendment filings
- Production capacity changes
- Change of factory location or layout
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Factory Expansion Approvals
Expanding production capacity, adding machinery or increasing workforce beyond licensed thresholds requires prior DIW approval. We manage the expansion application process.
- Expansion application preparation
- Upgraded category reclassification
- New machinery registration
- Environmental reassessment support
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Ongoing Compliance Management
Operating under a factory license involves continuous obligations. We monitor your compliance calendar and manage all ongoing DIW obligations on your behalf.
- Annual compliance reporting
- Environmental monitoring reports
- Safety and health condition tracking
- Integration with BOI reporting where applicable
Key Requirements
What the DIW Requires for a Factory License
Key elements assessed by the Department of Industrial Works during the factory license review process.
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Factory Site Approval
The factory premises must comply with local zoning regulations. Industrial operations are prohibited in residential and certain commercial zones.
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Machinery Schedule
A complete schedule of all machinery and equipment, including horsepower ratings, must be submitted. Each machine must be properly registered.
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Environmental Compliance
Factories must demonstrate compliance with environmental standards covering waste water discharge, air emissions, noise levels and hazardous waste management.
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Fire Safety & Building Compliance
Factory buildings must comply with building control regulations and fire safety standards. Fire suppression systems and emergency exits must be certified.
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Safety Officer Registration
Type 3 factories must employ a registered safety officer and establish a safety committee. Workplace safety plans must be documented.
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Corporate Documentation
Company registration documents, shareholder lists, director identification and evidence of authorized signatories are required for the license application.
Factory Type Comparison
Type 1 vs Type 2 vs Type 3 — At a Glance
A quick reference guide to Thailand's three factory categories under the Factory Act B.E. 2535.
| Feature | Type 1 | Type 2 | Type 3 |
|---|---|---|---|
| HP Threshold | 5–20 HP | 21–50 HP | 50+ HP |
| Worker Threshold | 7–20 workers | 21–50 workers | 50+ workers |
| Authorization Required | Notification only | Pre-operation notice | Full license required |
| Can Operate Immediately | ✓ Yes | ~ After 30-day period | ✗ Only after approval |
| DIW Site Inspection | ✗ Not required | ~ May be conducted | ✓ Mandatory |
| Environmental Assessment | ✗ Not required | ~ Basic requirements | ✓ Full assessment |
| Safety Officer Required | ✗ No | ~ Depends on activity | ✓ Mandatory |
| Processing Time | Immediate | 30 days | 30–90 business days |
| Annual Reporting | Minimal | Standard | Comprehensive |
Combined Incentives
Combining Your Factory License with BOI & Free Zone Benefits
A factory license is often the foundation of a broader incentive structure. Understanding how it intersects with BOI and Free Zone frameworks is key to maximizing your investment.
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Factory License + BOI
BOI-promoted manufacturers require a factory license alongside their BOI certificate. We coordinate both applications in parallel, ensuring your production operations are fully authorized and incentivized from day one.
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Factory License + IEAT Free Zone
Manufacturers operating within an IEAT Free Zone or Export Processing Zone require a factory license for their production activities within the zone. We manage both registrations as a unified process.
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CIT Exemption + Duty-Free Inputs
Combining BOI corporate income tax exemptions (up to 13 years) with IEAT Free Zone duty-free imports represents the maximum incentive package for manufacturers in Thailand.
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Machinery Depreciation & Accounting
Factory machinery registered under the DIW license requires proper asset registration and depreciation accounting. We ensure DIW machinery records align with your financial statements.
Our Process
How We Obtain Your Factory License
A structured, end-to-end approach — from classification to license in hand.
1
Step 1
Classification Assessment
We assess your machinery, workforce and activity to determine the correct factory type and applicable requirements.
2
Step 2
Document Preparation
We compile the full application dossier — factory plans, machinery schedules, environmental reports and corporate documents.
3
Step 3
DIW Submission
We submit the complete application to the Department of Industrial Works and manage all official correspondence.
4
Step 4
Site Inspection
We prepare your team and premises for the DIW site inspection, accompanying officers during the visit where applicable.
5
Step 5
License Issuance
Upon DIW approval, we obtain the factory license and brief you on all conditions attached to its operation.
6
Step 6
Ongoing Compliance
We manage annual reporting, environmental monitoring, renewal filing and any expansion applications throughout your operations.
Why Choose B-Accounting
Your Trusted Partner for Industrial Compliance in Thailand
Regulatory expertise combined with accounting and BOI advisory — all under one roof.
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Foreign Manufacturer Specialists
European-owned firm with extensive experience supporting foreign manufacturers navigating Thailand's industrial licensing, BOI and Free Zone regulatory environment.
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One-Stop Industrial Advisory
Factory license, BOI promotion, Free Zone registration, company setup, accounting, payroll and immigration — every service for your manufacturing operation under one engagement.
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Accounting & Regulatory Integration
We align your factory license machinery records with financial accounting, BOI investment tracking and DIW annual reports — eliminating discrepancies across frameworks.
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English, French & Thai
Full multilingual capability for clear communication with the DIW, IEAT, BOI and other Thai industrial authorities on your behalf.
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Proactive Compliance Management
We track renewal dates, environmental reporting deadlines, machinery change obligations and BOI conditions — so compliance never falls through the cracks.
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13+ Years of Experience
Over a decade supporting international manufacturing and industrial companies in Thailand across food processing, electronics, automotive, chemicals and more.
FAQ
Frequently Asked Questions
Common questions from manufacturers and industrial operators about the Factory License process in Thailand.
Does every manufacturing business in Thailand need a factory license?+
Not every business requires a formal license, but any operation that uses machinery with an aggregate power of 5 horsepower or more, or employs 7 or more workers in a production process, falls under the Factory Act and requires at minimum a Type 1 notification. Businesses operating below these thresholds are not classified as factories under the Act.
How long does it take to obtain a Type 3 factory license?+
A Type 3 factory license typically takes 30 to 90 business days from the date of submission of a complete application, including the DIW site inspection. Processing times vary depending on the nature of the industrial activity, the completeness of the application, and the workload at the relevant DIW regional office. Applications involving hazardous materials may require additional review time.
Can a factory license be transferred when a company changes ownership?+
A factory license is issued to a specific legal entity for a specific location and set of operations. When a company changes ownership through a share transfer, the existing license generally remains valid. However, if the factory is acquired through an asset purchase or a new company is established, a new factory license application is required. B-Accounting advises on the correct treatment of factory licenses in M&A transactions.
What happens if we add new machinery beyond what is listed on the license?+
Any addition of machinery not listed in the existing factory license, or any increase in aggregate machinery power, must be reported to and approved by the DIW before the new machinery is put into operation. If the addition causes the total HP to exceed the threshold for the current factory type, reclassification and a new or amended license may be required.
Is a factory license required for operations inside an IEAT Free Zone or BOI-promoted facility?+
Yes. BOI promotion and IEAT Free Zone status do not exempt a company from the requirement to hold a factory license under the Factory Act. These frameworks are complementary — a manufacturer within an IEAT Free Zone typically holds a factory license, an IEAT zone permit, and in many cases a BOI promotion certificate simultaneously. B-Accounting manages all three authorizations as a coordinated compliance program.
What environmental obligations apply to a Type 3 factory?+
Type 3 factories are subject to comprehensive environmental obligations including installation of waste water treatment systems meeting DIW discharge standards, air emission controls, noise level compliance, proper handling and disposal of hazardous industrial waste, and submission of periodic environmental monitoring reports to the DIW. Factories in certain high-impact sectors may also require Environmental Impact Assessment before license issuance.
Can B-Accounting assist with the full manufacturing setup including company registration and BOI?+
Yes. B-Accounting provides a complete, integrated service for foreign manufacturers entering Thailand — covering company registration, BOI application, factory license, Free Zone registration, accounting and tax setup, payroll, and visa and work permits for foreign employees. Managing all authorizations through a single advisor eliminates coordination gaps and ensures all regulatory frameworks are aligned from the outset.
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Ready to License Your
Factory in Thailand?
Our specialists will classify your operations, prepare the full application and manage the DIW process — so you can focus on production, not paperwork.